在C++中解析(拆分)字符串使用字符串定界符(标准C++)

发布于 2025-01-22 00:18:18 字数 394 浏览 0 评论 0 原文

我使用以下内容在C ++中解析一个字符串:

using namespace std;

string parsed,input="text to be parsed";
stringstream input_stringstream(input);

if (getline(input_stringstream,parsed,' '))
{
     // do some processing.
}

用单个CHAR定界符解析是可以的。但是,如果我想将字符串用作定界符怎么办。

示例:我想拆分:

scott>=tiger

> = 作为定界符,以便我可以得到Scott和Tiger。

I am parsing a string in C++ using the following:

using namespace std;

string parsed,input="text to be parsed";
stringstream input_stringstream(input);

if (getline(input_stringstream,parsed,' '))
{
     // do some processing.
}

Parsing with a single char delimiter is fine. But what if I want to use a string as delimiter.

Example: I want to split:

scott>=tiger

with >= as delimiter so that I can get scott and tiger.

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评论(30

执笏见 2025-01-29 00:18:19

我做这个解决方案。它非常简单,所有打印/值都在循环中(循环后不需要检查)。

#include <iostream>
#include <string>

using std::cout;
using std::string;

int main() {
    string s = "it-+is-+working!";
    string d = "-+";

    int firstFindI = 0;
    int secendFindI = 0;
    while (secendFindI != string::npos)
    {
        secendFindI = s.find(d, firstFindI);
        cout << s.substr(firstFindI, secendFindI - firstFindI) << "\n"; // print sliced part
        firstFindI = secendFindI + d.size(); // add to the search index
    }
}

感谢@steveward改善了这个答案。

I make this solution. It is very simple, all the prints/values are in the loop (no need to check after the loop).

#include <iostream>
#include <string>

using std::cout;
using std::string;

int main() {
    string s = "it-+is-+working!";
    string d = "-+";

    int firstFindI = 0;
    int secendFindI = 0;
    while (secendFindI != string::npos)
    {
        secendFindI = s.find(d, firstFindI);
        cout << s.substr(firstFindI, secendFindI - firstFindI) << "\n"; // print sliced part
        firstFindI = secendFindI + d.size(); // add to the search index
    }
}

Thanks to @SteveWard for improving this answer.

深空失忆 2025-01-29 00:18:19

这是一种完整的方法,可以将字符串在任何定界符上拆分并返回切碎的字符串的向量。

这是Ryanbwork的答案的改编。但是,他的检查:如果(token!= mystring)如果字符串中有重复元素,则会给出错误的结果。这是我解决这个问题的方法。

vector<string> Split(string mystring, string delimiter)
{
    vector<string> subStringList;
    string token;
    while (true)
    {
        size_t findfirst = mystring.find(delimiter);
        if (findfirst == string::npos) //find returns npos if it couldn't find the delimiter anymore
        {
            subStringList.push_back(mystring); //push back the final piece of mystring
            return subStringList;
        }
        token = mystring.substr(0, mystring.find(delimiter));
        mystring = mystring.substr(mystring.find(delimiter) + delimiter.size());
        subStringList.push_back(token);
    }
    return subStringList;
}

This is a complete method that splits the string on any delimiter and returns a vector of the chopped up strings.

It is an adaptation from the answer from ryanbwork. However, his check for: if(token != mystring) gives wrong results if you have repeating elements in your string. This is my solution to that problem.

vector<string> Split(string mystring, string delimiter)
{
    vector<string> subStringList;
    string token;
    while (true)
    {
        size_t findfirst = mystring.find(delimiter);
        if (findfirst == string::npos) //find returns npos if it couldn't find the delimiter anymore
        {
            subStringList.push_back(mystring); //push back the final piece of mystring
            return subStringList;
        }
        token = mystring.substr(0, mystring.find(delimiter));
        mystring = mystring.substr(mystring.find(delimiter) + delimiter.size());
        subStringList.push_back(token);
    }
    return subStringList;
}
这样的小城市 2025-01-29 00:18:19

由于这是 c ++ split String 或类似的顶级堆栈溢出的Google搜索结果,因此我将发布一个完整的,复制/粘贴可运行的示例,显示这两种方法。

SplitString 使用 stringstream (在大多数情况下可能是更好,更容易的选项)

splitstring2 use 查找 subSttr (一种更多的手动方法)

// SplitString.cpp

#include <iostream>
#include <vector>
#include <string>
#include <sstream>

// function prototypes
std::vector<std::string> splitString(const std::string& str, char delim);
std::vector<std::string> splitString2(const std::string& str, char delim);
std::string getSubstring(const std::string& str, int leftIdx, int rightIdx);


int main(void)
{
  // Test cases - all will pass
  
  std::string str = "ab,cd,ef";
  //std::string str = "abcdef";
  //std::string str = "";
  //std::string str = ",cd,ef";
  //std::string str = "ab,cd,";   // behavior of splitString and splitString2 is different for this final case only, if this case matters to you choose which one you need as applicable
  
  
  std::vector<std::string> tokens = splitString(str, ',');
  
  std::cout << "tokens: " << "\n";
  
  if (tokens.empty())
  {
    std::cout << "(tokens is empty)" << "\n";
  }
  else
  {
    for (auto& token : tokens)
    {
      if (token == "") std::cout << "(empty string)" << "\n";
      else std::cout << token << "\n";
    }
  }
    
  return 0;
}

std::vector<std::string> splitString(const std::string& str, char delim)
{
  std::vector<std::string> tokens;
  
  if (str == "") return tokens;
  
  std::string currentToken;
  
  std::stringstream ss(str);
  
  while (std::getline(ss, currentToken, delim))
  {
    tokens.push_back(currentToken);
  }
  
  return tokens;
}

std::vector<std::string> splitString2(const std::string& str, char delim)
{
  std::vector<std::string> tokens;
  
  if (str == "") return tokens;
  
  int leftIdx = 0;
  
  int delimIdx = str.find(delim);
  
  int rightIdx;
  
  while (delimIdx != std::string::npos)
  {
    rightIdx = delimIdx - 1;
    
    std::string token = getSubstring(str, leftIdx, rightIdx);
    tokens.push_back(token);
    
    // prep for next time around
    leftIdx = delimIdx + 1;
    
    delimIdx = str.find(delim, delimIdx + 1);
  }
  
  rightIdx = str.size() - 1;
  
  std::string token = getSubstring(str, leftIdx, rightIdx);
  tokens.push_back(token);
  
  return tokens;
}

std::string getSubstring(const std::string& str, int leftIdx, int rightIdx)
{
  return str.substr(leftIdx, rightIdx - leftIdx + 1);
}

Since this is the top-rated Stack Overflow Google search result for C++ split string or similar, I'll post a complete, copy/paste runnable example that shows both methods.

splitString uses stringstream (probably the better and easier option in most cases)

splitString2 uses find and substr (a more manual approach)

// SplitString.cpp

#include <iostream>
#include <vector>
#include <string>
#include <sstream>

// function prototypes
std::vector<std::string> splitString(const std::string& str, char delim);
std::vector<std::string> splitString2(const std::string& str, char delim);
std::string getSubstring(const std::string& str, int leftIdx, int rightIdx);


int main(void)
{
  // Test cases - all will pass
  
  std::string str = "ab,cd,ef";
  //std::string str = "abcdef";
  //std::string str = "";
  //std::string str = ",cd,ef";
  //std::string str = "ab,cd,";   // behavior of splitString and splitString2 is different for this final case only, if this case matters to you choose which one you need as applicable
  
  
  std::vector<std::string> tokens = splitString(str, ',');
  
  std::cout << "tokens: " << "\n";
  
  if (tokens.empty())
  {
    std::cout << "(tokens is empty)" << "\n";
  }
  else
  {
    for (auto& token : tokens)
    {
      if (token == "") std::cout << "(empty string)" << "\n";
      else std::cout << token << "\n";
    }
  }
    
  return 0;
}

std::vector<std::string> splitString(const std::string& str, char delim)
{
  std::vector<std::string> tokens;
  
  if (str == "") return tokens;
  
  std::string currentToken;
  
  std::stringstream ss(str);
  
  while (std::getline(ss, currentToken, delim))
  {
    tokens.push_back(currentToken);
  }
  
  return tokens;
}

std::vector<std::string> splitString2(const std::string& str, char delim)
{
  std::vector<std::string> tokens;
  
  if (str == "") return tokens;
  
  int leftIdx = 0;
  
  int delimIdx = str.find(delim);
  
  int rightIdx;
  
  while (delimIdx != std::string::npos)
  {
    rightIdx = delimIdx - 1;
    
    std::string token = getSubstring(str, leftIdx, rightIdx);
    tokens.push_back(token);
    
    // prep for next time around
    leftIdx = delimIdx + 1;
    
    delimIdx = str.find(delim, delimIdx + 1);
  }
  
  rightIdx = str.size() - 1;
  
  std::string token = getSubstring(str, leftIdx, rightIdx);
  tokens.push_back(token);
  
  return tokens;
}

std::string getSubstring(const std::string& str, int leftIdx, int rightIdx)
{
  return str.substr(leftIdx, rightIdx - leftIdx + 1);
}
偏爱自由 2025-01-29 00:18:19

另一个答案:在这里,我正在使用 find_first_not_of 字符串函数返回 not 不匹配的第一个字符的位置匹配指定的任何字符在特征中。

size_t find_first_not_of(const string& delim, size_t pos = 0) const noexcept;

示例:

int main()
{
    size_t start = 0, end = 0;
    std::string str = "scott>=tiger>=cat";
    std::string delim = ">=";
    while ((start = str.find_first_not_of(delim, end)) != std::string::npos)
    {
        end = str.find(delim, start); // finds the 'first' occurance from the 'start'
        std::cout << str.substr(start, end - start)<<std::endl; // extract substring
    }
    return 0;
}

输出:

    scott
    tiger
    cat

Yet another answer: Here I'm using find_first_not_of string function which returns the position of the first character that does not match any of the characters specified in the delim.

size_t find_first_not_of(const string& delim, size_t pos = 0) const noexcept;

Example:

int main()
{
    size_t start = 0, end = 0;
    std::string str = "scott>=tiger>=cat";
    std::string delim = ">=";
    while ((start = str.find_first_not_of(delim, end)) != std::string::npos)
    {
        end = str.find(delim, start); // finds the 'first' occurance from the 'start'
        std::cout << str.substr(start, end - start)<<std::endl; // extract substring
    }
    return 0;
}

Output:

    scott
    tiger
    cat
灰色世界里的红玫瑰 2025-01-29 00:18:19

如果您不想修改字符串(如Vincenzo pii的答案中)也希望输出最后一个令牌,则可能需要使用此方法:

inline std::vector<std::string> splitString( const std::string &s, const std::string &delimiter ){
    std::vector<std::string> ret;
    size_t start = 0;
    size_t end = 0;
    size_t len = 0;
    std::string token;
    do{ end = s.find(delimiter,start); 
        len = end - start;
        token = s.substr(start, len);
        ret.emplace_back( token );
        start += len + delimiter.length();
        std::cout << token << std::endl;
    }while ( end != std::string::npos );
    return ret;
}

If you do not want to modify the string (as in the answer by Vincenzo Pii) and want to output the last token as well, you may want to use this approach:

inline std::vector<std::string> splitString( const std::string &s, const std::string &delimiter ){
    std::vector<std::string> ret;
    size_t start = 0;
    size_t end = 0;
    size_t len = 0;
    std::string token;
    do{ end = s.find(delimiter,start); 
        len = end - start;
        token = s.substr(start, len);
        ret.emplace_back( token );
        start += len + delimiter.length();
        std::cout << token << std::endl;
    }while ( end != std::string::npos );
    return ret;
}
木落 2025-01-29 00:18:19

这是一个简洁的拆分功能。我决定让背对背的定界器作为一个空字符串返回,但是您可以轻松检查子字符串是否为空,并且如果是空字符串,则不会将其添加到向量。

#include <vector>
#include <string>
using namespace std;



vector<string> split(string to_split, string delimiter) {
    size_t pos = 0;
    vector<string> matches{};
    do {
        pos = to_split.find(delimiter);
        int change_end;
        if (pos == string::npos) {
            pos = to_split.length() - 1;
            change_end = 1;
        }
        else {
            change_end = 0;
        }
        matches.push_back(to_split.substr(0, pos+change_end));
        
        to_split.erase(0, pos+1);

    }
    while (!to_split.empty());
    return matches;

}

Here's a concise split function. I decided to have back to back delimiters return as an empty string but you could easily check that if the substring is empty and not add it to the vector if it is.

#include <vector>
#include <string>
using namespace std;



vector<string> split(string to_split, string delimiter) {
    size_t pos = 0;
    vector<string> matches{};
    do {
        pos = to_split.find(delimiter);
        int change_end;
        if (pos == string::npos) {
            pos = to_split.length() - 1;
            change_end = 1;
        }
        else {
            change_end = 0;
        }
        matches.push_back(to_split.substr(0, pos+change_end));
        
        to_split.erase(0, pos+1);

    }
    while (!to_split.empty());
    return matches;

}
谁与争疯 2025-01-29 00:18:19

此方法使用 string find string substr

vector<string> split(const string& str,const string delim){
vector<string> vtokens; 
size_t start = 0;
size_t end = 0;
while((end = str.find(delim,start))!=string::npos){
    vtokens.push_back(str.substr(start,end-start));
    start = end +1;
}
vtokens.push_back(str.substr(start));
return vtokens;
}

This method use string find and string substr

vector<string> split(const string& str,const string delim){
vector<string> vtokens; 
size_t start = 0;
size_t end = 0;
while((end = str.find(delim,start))!=string::npos){
    vtokens.push_back(str.substr(start,end-start));
    start = end +1;
}
vtokens.push_back(str.substr(start));
return vtokens;
}
迎风吟唱 2025-01-29 00:18:19
#include<iostream>
#include<algorithm>
using namespace std;

int split_count(string str,char delimit){
return count(str.begin(),str.end(),delimit);
}

void split(string str,char delimit,string res[]){
int a=0,i=0;
while(a<str.size()){
res[i]=str.substr(a,str.find(delimit));
a+=res[i].size()+1;
i++;
}
}

int main(){

string a="abc.xyz.mno.def";
int x=split_count(a,'.')+1;
string res[x];
split(a,'.',res);

for(int i=0;i<x;i++)
cout<<res[i]<<endl;
  return 0;
}

PS:仅当分裂后的字符串长度相等时才起作用

#include<iostream>
#include<algorithm>
using namespace std;

int split_count(string str,char delimit){
return count(str.begin(),str.end(),delimit);
}

void split(string str,char delimit,string res[]){
int a=0,i=0;
while(a<str.size()){
res[i]=str.substr(a,str.find(delimit));
a+=res[i].size()+1;
i++;
}
}

int main(){

string a="abc.xyz.mno.def";
int x=split_count(a,'.')+1;
string res[x];
split(a,'.',res);

for(int i=0;i<x;i++)
cout<<res[i]<<endl;
  return 0;
}

P.S: Works only if the lengths of the strings after splitting are equal

木槿暧夏七纪年 2025-01-29 00:18:19
std::vector<std::string> parse(std::string str,std::string delim){
    std::vector<std::string> tokens;
    char *str_c = strdup(str.c_str()); 
    char* token = NULL;

    token = strtok(str_c, delim.c_str()); 
    while (token != NULL) { 
        tokens.push_back(std::string(token));  
        token = strtok(NULL, delim.c_str()); 
    }

    delete[] str_c;

    return tokens;
}
std::vector<std::string> parse(std::string str,std::string delim){
    std::vector<std::string> tokens;
    char *str_c = strdup(str.c_str()); 
    char* token = NULL;

    token = strtok(str_c, delim.c_str()); 
    while (token != NULL) { 
        tokens.push_back(std::string(token));  
        token = strtok(NULL, delim.c_str()); 
    }

    delete[] str_c;

    return tokens;
}
感性不性感 2025-01-29 00:18:19

功能:

std::vector<std::string> WSJCppCore::split(const std::string& sWhat, const std::string& sDelim) {
    std::vector<std::string> vRet;
    size_t nPos = 0;
    size_t nLen = sWhat.length();
    size_t nDelimLen = sDelim.length();
    while (nPos < nLen) {
        std::size_t nFoundPos = sWhat.find(sDelim, nPos);
        if (nFoundPos != std::string::npos) {
            std::string sToken = sWhat.substr(nPos, nFoundPos - nPos);
            vRet.push_back(sToken);
            nPos = nFoundPos + nDelimLen;
            if (nFoundPos + nDelimLen == nLen) { // last delimiter
                vRet.push_back("");
            }
        } else {
            std::string sToken = sWhat.substr(nPos, nLen - nPos);
            vRet.push_back(sToken);
            break;
        }
    }
    return vRet;
}

单位测试:

bool UnitTestSplit::run() {
bool bTestSuccess = true;

    struct LTest {
        LTest(
            const std::string &sStr,
            const std::string &sDelim,
            const std::vector<std::string> &vExpectedVector
        ) {
            this->sStr = sStr;
            this->sDelim = sDelim;
            this->vExpectedVector = vExpectedVector;
        };
        std::string sStr;
        std::string sDelim;
        std::vector<std::string> vExpectedVector;
    };
    std::vector<LTest> tests;
    tests.push_back(LTest("1 2 3 4 5", " ", {"1", "2", "3", "4", "5"}));
    tests.push_back(LTest("|1f|2п|3%^|44354|5kdasjfdre|2", "|", {"", "1f", "2п", "3%^", "44354", "5kdasjfdre", "2"}));
    tests.push_back(LTest("|1f|2п|3%^|44354|5kdasjfdre|", "|", {"", "1f", "2п", "3%^", "44354", "5kdasjfdre", ""}));
    tests.push_back(LTest("some1 => some2 => some3", "=>", {"some1 ", " some2 ", " some3"}));
    tests.push_back(LTest("some1 => some2 => some3 =>", "=>", {"some1 ", " some2 ", " some3 ", ""}));

    for (int i = 0; i < tests.size(); i++) {
        LTest test = tests[i];
        std::string sPrefix = "test" + std::to_string(i) + "(\"" + test.sStr + "\")";
        std::vector<std::string> vSplitted = WSJCppCore::split(test.sStr, test.sDelim);
        compareN(bTestSuccess, sPrefix + ": size", vSplitted.size(), test.vExpectedVector.size());
        int nMin = std::min(vSplitted.size(), test.vExpectedVector.size());
        for (int n = 0; n < nMin; n++) {
            compareS(bTestSuccess, sPrefix + ", element: " + std::to_string(n), vSplitted[n], test.vExpectedVector[n]);
        }
    }

    return bTestSuccess;
}

Function:

std::vector<std::string> WSJCppCore::split(const std::string& sWhat, const std::string& sDelim) {
    std::vector<std::string> vRet;
    size_t nPos = 0;
    size_t nLen = sWhat.length();
    size_t nDelimLen = sDelim.length();
    while (nPos < nLen) {
        std::size_t nFoundPos = sWhat.find(sDelim, nPos);
        if (nFoundPos != std::string::npos) {
            std::string sToken = sWhat.substr(nPos, nFoundPos - nPos);
            vRet.push_back(sToken);
            nPos = nFoundPos + nDelimLen;
            if (nFoundPos + nDelimLen == nLen) { // last delimiter
                vRet.push_back("");
            }
        } else {
            std::string sToken = sWhat.substr(nPos, nLen - nPos);
            vRet.push_back(sToken);
            break;
        }
    }
    return vRet;
}

Unit-tests:

bool UnitTestSplit::run() {
bool bTestSuccess = true;

    struct LTest {
        LTest(
            const std::string &sStr,
            const std::string &sDelim,
            const std::vector<std::string> &vExpectedVector
        ) {
            this->sStr = sStr;
            this->sDelim = sDelim;
            this->vExpectedVector = vExpectedVector;
        };
        std::string sStr;
        std::string sDelim;
        std::vector<std::string> vExpectedVector;
    };
    std::vector<LTest> tests;
    tests.push_back(LTest("1 2 3 4 5", " ", {"1", "2", "3", "4", "5"}));
    tests.push_back(LTest("|1f|2п|3%^|44354|5kdasjfdre|2", "|", {"", "1f", "2п", "3%^", "44354", "5kdasjfdre", "2"}));
    tests.push_back(LTest("|1f|2п|3%^|44354|5kdasjfdre|", "|", {"", "1f", "2п", "3%^", "44354", "5kdasjfdre", ""}));
    tests.push_back(LTest("some1 => some2 => some3", "=>", {"some1 ", " some2 ", " some3"}));
    tests.push_back(LTest("some1 => some2 => some3 =>", "=>", {"some1 ", " some2 ", " some3 ", ""}));

    for (int i = 0; i < tests.size(); i++) {
        LTest test = tests[i];
        std::string sPrefix = "test" + std::to_string(i) + "(\"" + test.sStr + "\")";
        std::vector<std::string> vSplitted = WSJCppCore::split(test.sStr, test.sDelim);
        compareN(bTestSuccess, sPrefix + ": size", vSplitted.size(), test.vExpectedVector.size());
        int nMin = std::min(vSplitted.size(), test.vExpectedVector.size());
        for (int n = 0; n < nMin; n++) {
            compareS(bTestSuccess, sPrefix + ", element: " + std::to_string(n), vSplitted[n], test.vExpectedVector[n]);
        }
    }

    return bTestSuccess;
}
她如夕阳 2025-01-29 00:18:19

我使用指针算术。内部为字符串区别仪,如果您与char系列满足,只需简单地删除内部即可。我希望这是正确的。如果您发现任何错误或改进,请发表评论。

std::vector<std::string> split(std::string s, std::string delim)
{
    char *p = &s[0];
    char *d = &delim[0];
    std::vector<std::string> res = {""};

    do
    {
        bool is_delim = true;
        char *pp = p;
        char *dd = d;
        while (*dd && is_delim == true)
            if (*pp++ != *dd++)
                is_delim = false;

        if (is_delim)
        {
            p = pp - 1;
            res.push_back("");
        }
        else
            *(res.rbegin()) += *p;
    } while (*p++);

    return res;
}

i use pointer arithmetic. inner while for string delimeter if you satify with char delim just remove inner while simply. i hope it is correct. if you notice any mistake or improve please leave the comment.

std::vector<std::string> split(std::string s, std::string delim)
{
    char *p = &s[0];
    char *d = &delim[0];
    std::vector<std::string> res = {""};

    do
    {
        bool is_delim = true;
        char *pp = p;
        char *dd = d;
        while (*dd && is_delim == true)
            if (*pp++ != *dd++)
                is_delim = false;

        if (is_delim)
        {
            p = pp - 1;
            res.push_back("");
        }
        else
            *(res.rbegin()) += *p;
    } while (*p++);

    return res;
}
蹲在坟头点根烟 2025-01-29 00:18:19
template<typename C, typename T>
auto insert_in_container(C& c, T&& t) -> decltype(c.push_back(std::forward<T>(t)), void()) {
    c.push_back(std::forward<T>(t));
}
template<typename C, typename T>
auto insert_in_container(C& c, T&& t) -> decltype(c.insert(std::forward<T>(t)), void()) {
    c.insert(std::forward<T>(t));
}
template<typename Container>
Container splitR(const std::string& input, const std::string& delims) {
    Container out;
    size_t delims_len = delims.size();
    auto begIdx = 0u;
    auto endIdx = input.find(delims, begIdx);
    if (endIdx == std::string::npos && input.size() != 0u) {
        insert_in_container(out, input);
    }
    else {
        size_t w = 0;
        while (endIdx != std::string::npos) {
            w = endIdx - begIdx;
            if (w != 0) insert_in_container(out, input.substr(begIdx, w));
            begIdx = endIdx + delims_len;
            endIdx = input.find(delims, begIdx);
        }
        w = input.length() - begIdx;
        if (w != 0) insert_in_container(out, input.substr(begIdx, w));
    }
    return out;
}
template<typename C, typename T>
auto insert_in_container(C& c, T&& t) -> decltype(c.push_back(std::forward<T>(t)), void()) {
    c.push_back(std::forward<T>(t));
}
template<typename C, typename T>
auto insert_in_container(C& c, T&& t) -> decltype(c.insert(std::forward<T>(t)), void()) {
    c.insert(std::forward<T>(t));
}
template<typename Container>
Container splitR(const std::string& input, const std::string& delims) {
    Container out;
    size_t delims_len = delims.size();
    auto begIdx = 0u;
    auto endIdx = input.find(delims, begIdx);
    if (endIdx == std::string::npos && input.size() != 0u) {
        insert_in_container(out, input);
    }
    else {
        size_t w = 0;
        while (endIdx != std::string::npos) {
            w = endIdx - begIdx;
            if (w != 0) insert_in_container(out, input.substr(begIdx, w));
            begIdx = endIdx + delims_len;
            endIdx = input.find(delims, begIdx);
        }
        w = input.length() - begIdx;
        if (w != 0) insert_in_container(out, input.substr(begIdx, w));
    }
    return out;
}
匿名。 2025-01-29 00:18:19

一个简单的解决方案是 -

您可以使用 strtok 根据多级定界符进行界定。
请记住使用 strdup ,以使Orignal String不会突变。

#include <stdio.h>
#include <string.h>
const char* str = "scott>=tiger";
char *token = strtok(strdup(str), ">=");
while (token != NULL)
    {
        printf("%s\n", token);
        token = strtok(NULL, ">=");
    }

A simpler solution would be -

You can use strtok to delimit on the basis of multichar delimiter.
Remember to use strdup so that the orignal string isn't mutated.

#include <stdio.h>
#include <string.h>
const char* str = "scott>=tiger";
char *token = strtok(strdup(str), ">=");
while (token != NULL)
    {
        printf("%s\n", token);
        token = strtok(NULL, ">=");
    }
琴流音 2025-01-29 00:18:19

我浏览了答案,但还没有看到一个基于迭代的方法,该方法可以馈入范围循环,所以我做了一个。

这使用C ++ 17 String_views,因此不应分配字符串的副本。

struct StringSplit
{
    struct Iterator
    {
        size_t tokenStart_ = 0;
        size_t tokenEnd_ = 0;
        std::string str_;
        std::string_view view_;
        std::string delimiter_;
        bool done_ = false;

        Iterator()
        {
            // End iterator.
            done_ = true;
        }

        Iterator(std::string str, std::string delimiter)
            : str_{std::move(str)}, view_{str_}, delimiter_{
                                                     std::move(delimiter)}
        {
            tokenEnd_ = view_.find(delimiter_, tokenStart_);
        }

        std::string_view operator*()
        {
            return view_.substr(tokenStart_, tokenEnd_ - tokenStart_);
        }

        Iterator &operator++()
        {
            if (tokenEnd_ == std::string::npos)
            {
                done_ = true;
                return *this;
            }

            tokenStart_ = tokenEnd_ + delimiter_.size();
            tokenEnd_ = view_.find(delimiter_, tokenStart_);
            return *this;
        }

        bool operator!=(Iterator &other)
        {
            // We only check if both points to the end.
            if (done_ && other.done_)
            {
                return false;
            }

            return true;
        }
    };

    Iterator beginIter_;

    StringSplit(std::string str, std::string delim)
        : beginIter_{std::move(str), std::move(delim)}
    {
    }

    Iterator begin()
    {
        return beginIter_;
    }

    Iterator end()
    {
        return Iterator{};
    }
};

示例用法将是:

int main()
{
    for (auto token : StringSplit{"<>foo<>bar<><>bar<><>baz<><>", "<>"})
    {
        std::cout << "TOKEN: '" << token << "'" << std::endl;
    }
}

哪个打印:

TOKEN: ''
TOKEN: 'foo'
TOKEN: 'bar'
TOKEN: ''
TOKEN: 'bar'
TOKEN: ''
TOKEN: 'baz'
TOKEN: ''
TOKEN: ''

它在字符串的开头和结尾处正确处理空条目。

I looked through the answers and haven't seen an iterator based approach that can be fed into a range loop, so I made one.

This uses C++17 string_views so it shouldn't allocate copies of the string.

struct StringSplit
{
    struct Iterator
    {
        size_t tokenStart_ = 0;
        size_t tokenEnd_ = 0;
        std::string str_;
        std::string_view view_;
        std::string delimiter_;
        bool done_ = false;

        Iterator()
        {
            // End iterator.
            done_ = true;
        }

        Iterator(std::string str, std::string delimiter)
            : str_{std::move(str)}, view_{str_}, delimiter_{
                                                     std::move(delimiter)}
        {
            tokenEnd_ = view_.find(delimiter_, tokenStart_);
        }

        std::string_view operator*()
        {
            return view_.substr(tokenStart_, tokenEnd_ - tokenStart_);
        }

        Iterator &operator++()
        {
            if (tokenEnd_ == std::string::npos)
            {
                done_ = true;
                return *this;
            }

            tokenStart_ = tokenEnd_ + delimiter_.size();
            tokenEnd_ = view_.find(delimiter_, tokenStart_);
            return *this;
        }

        bool operator!=(Iterator &other)
        {
            // We only check if both points to the end.
            if (done_ && other.done_)
            {
                return false;
            }

            return true;
        }
    };

    Iterator beginIter_;

    StringSplit(std::string str, std::string delim)
        : beginIter_{std::move(str), std::move(delim)}
    {
    }

    Iterator begin()
    {
        return beginIter_;
    }

    Iterator end()
    {
        return Iterator{};
    }
};

And example usage would be:

int main()
{
    for (auto token : StringSplit{"<>foo<>bar<><>bar<><>baz<><>", "<>"})
    {
        std::cout << "TOKEN: '" << token << "'" << std::endl;
    }
}

Which prints:

TOKEN: ''
TOKEN: 'foo'
TOKEN: 'bar'
TOKEN: ''
TOKEN: 'bar'
TOKEN: ''
TOKEN: 'baz'
TOKEN: ''
TOKEN: ''

It properly handles empty entries at the beginning and end of the string.

花心好男孩 2025-01-29 00:18:19

这是使用库和 boost范围库。该解决方案的灵感来自stringalgo库文档中的(谦虚)建议,请参阅 split 部分。

以下是一个完整的程序,具有 split_with_string 函数以及综合测试 - 与godbolt尝试

#include <iostream>
#include <string>
#include <vector>
#include <boost/algorithm/string.hpp>
#include <boost/range/iterator_range.hpp>

std::vector<std::string> split_with_string(std::string_view s, std::string_view search) 
{
    if (search.empty()) return {std::string{s}};

    std::vector<boost::iterator_range<std::string_view::iterator>> found;
    boost::algorithm::ifind_all(found, s, search);
    if (found.empty()) return {};

    std::vector<std::string> parts;
    parts.reserve(found.size() + 2); // a bit more

    std::string_view::iterator part_begin = s.cbegin(), part_end;
    for (auto& split_found : found)
    {
        // do not skip empty extracts
        part_end = split_found.begin();
        parts.emplace_back(part_begin, part_end);
        part_begin = split_found.end();
    }
    if (part_end != s.end())
        parts.emplace_back(part_begin, s.end());

    return parts;
}

#define TEST(expr) std::cout << ((!(expr)) ? "FAIL" : "PASS") << ": " #expr "\t" << std::endl

int main()
{
    auto s0 = split_with_string("adsf-+qwret-+nvfkbdsj", "");
    TEST(s0.size() == 1);
    TEST(s0.front() == "adsf-+qwret-+nvfkbdsj");
    auto s1 = split_with_string("adsf-+qwret-+nvfkbdsj", "-+");
    TEST(s1.size() == 3);
    TEST(s1.front() == "adsf");
    TEST(s1.back() == "nvfkbdsj");
    auto s2 = split_with_string("-+adsf-+qwret-+nvfkbdsj-+", "-+");
    TEST(s2.size() == 5);
    TEST(s2.front() == "");
    TEST(s2.back() == "");
    auto s3 = split_with_string("-+adsf-+qwret-+nvfkbdsj", "-+");
    TEST(s3.size() == 4);
    TEST(s3.front() == "");
    TEST(s3.back() == "nvfkbdsj");
    auto s4 = split_with_string("adsf-+qwret-+nvfkbdsj-+", "-+");
    TEST(s4.size() == 4);
    TEST(s4.front() == "adsf");
    TEST(s4.back() == "");
    auto s5 = split_with_string("dbo.abc", "dbo.");
    TEST(s5.size() == 2);
    TEST(s5.front() == "");
    TEST(s5.back() == "abc");
    auto s6 = split_with_string("dbo.abc", ".");
    TEST(s6.size() == 2);
    TEST(s6.front() == "dbo");
    TEST(s6.back() == "abc");
}

测试输出:

PASS: s0.size() == 1    
PASS: s0.front() == "adsf-+qwret-+nvfkbdsj" 
PASS: s1.size() == 3    
PASS: s1.front() == "adsf"  
PASS: s1.back() == "nvfkbdsj"   
PASS: s2.size() == 5    
PASS: s2.front() == ""  
PASS: s2.back() == ""   
PASS: s3.size() == 4    
PASS: s3.front() == ""  
PASS: s3.back() == "nvfkbdsj"   
PASS: s4.size() == 4    
PASS: s4.front() == "adsf"  
PASS: s4.back() == ""   
PASS: s5.size() == 2    
PASS: s5.front() == ""  
PASS: s5.back() == "abc"    
PASS: s6.size() == 2    
PASS: s6.front() == "dbo"   
PASS: s6.back() == "abc"    

Here is an example of splitting a string with another string using Boost String Algorithms library and Boost Range library. The solution is inspired with (modest) suggestion from the the StringAlgo library documentation, see the Split section.

Below is a complete program with the split_with_string function as well as comprehensive test - try it with godbolt:

#include <iostream>
#include <string>
#include <vector>
#include <boost/algorithm/string.hpp>
#include <boost/range/iterator_range.hpp>

std::vector<std::string> split_with_string(std::string_view s, std::string_view search) 
{
    if (search.empty()) return {std::string{s}};

    std::vector<boost::iterator_range<std::string_view::iterator>> found;
    boost::algorithm::ifind_all(found, s, search);
    if (found.empty()) return {};

    std::vector<std::string> parts;
    parts.reserve(found.size() + 2); // a bit more

    std::string_view::iterator part_begin = s.cbegin(), part_end;
    for (auto& split_found : found)
    {
        // do not skip empty extracts
        part_end = split_found.begin();
        parts.emplace_back(part_begin, part_end);
        part_begin = split_found.end();
    }
    if (part_end != s.end())
        parts.emplace_back(part_begin, s.end());

    return parts;
}

#define TEST(expr) std::cout << ((!(expr)) ? "FAIL" : "PASS") << ": " #expr "\t" << std::endl

int main()
{
    auto s0 = split_with_string("adsf-+qwret-+nvfkbdsj", "");
    TEST(s0.size() == 1);
    TEST(s0.front() == "adsf-+qwret-+nvfkbdsj");
    auto s1 = split_with_string("adsf-+qwret-+nvfkbdsj", "-+");
    TEST(s1.size() == 3);
    TEST(s1.front() == "adsf");
    TEST(s1.back() == "nvfkbdsj");
    auto s2 = split_with_string("-+adsf-+qwret-+nvfkbdsj-+", "-+");
    TEST(s2.size() == 5);
    TEST(s2.front() == "");
    TEST(s2.back() == "");
    auto s3 = split_with_string("-+adsf-+qwret-+nvfkbdsj", "-+");
    TEST(s3.size() == 4);
    TEST(s3.front() == "");
    TEST(s3.back() == "nvfkbdsj");
    auto s4 = split_with_string("adsf-+qwret-+nvfkbdsj-+", "-+");
    TEST(s4.size() == 4);
    TEST(s4.front() == "adsf");
    TEST(s4.back() == "");
    auto s5 = split_with_string("dbo.abc", "dbo.");
    TEST(s5.size() == 2);
    TEST(s5.front() == "");
    TEST(s5.back() == "abc");
    auto s6 = split_with_string("dbo.abc", ".");
    TEST(s6.size() == 2);
    TEST(s6.front() == "dbo");
    TEST(s6.back() == "abc");
}

Tests output:

PASS: s0.size() == 1    
PASS: s0.front() == "adsf-+qwret-+nvfkbdsj" 
PASS: s1.size() == 3    
PASS: s1.front() == "adsf"  
PASS: s1.back() == "nvfkbdsj"   
PASS: s2.size() == 5    
PASS: s2.front() == ""  
PASS: s2.back() == ""   
PASS: s3.size() == 4    
PASS: s3.front() == ""  
PASS: s3.back() == "nvfkbdsj"   
PASS: s4.size() == 4    
PASS: s4.front() == "adsf"  
PASS: s4.back() == ""   
PASS: s5.size() == 2    
PASS: s5.front() == ""  
PASS: s5.back() == "abc"    
PASS: s6.size() == 2    
PASS: s6.front() == "dbo"   
PASS: s6.back() == "abc"    
她如夕阳 2025-01-29 00:18:18

您可以使用 std :: string :: string :: find() 功能要找到字符串定界符的位置,然后使用 std :: string :: substr() 获得一个令牌。

示例:

std::string s = "scott>=tiger";
std::string delimiter = ">=";
std::string token = s.substr(0, s.find(delimiter)); // token is "scott"
  • 查找(const String&str,size_t pos = 0)函数返回字符串中 str 的首次出现的位置=“ http://en.cppreference.com/w/cpp/string/basic_string/npos” rel =“ noreferrer”> npos 如果找不到字符串。


  • substr(size_t pos = 0,size_t n = npos)函数返回对象的子字符串,从位置开始 pos 和长度 npos < /代码>。



如果您有多个定界符,则提取一个令牌后,可以将其删除(包括定界符)继续进行后续提取(如果要保留原始字符串,只需使用 s = s.substr(pos + deleimiter) .length()); ):

s.erase(0, s.find(delimiter) + delimiter.length());

这样,您可以轻松地循环获取每个令牌。

完整的示例

std::vector<std::string> split(const std::string& s, const std::string& delimiter) {
    std::vector<std::string> tokens;
    size_t pos = 0;
    std::string token;
    while ((pos = s.find(delimiter)) != std::string::npos) {
        token = s.substr(0, pos);
        tokens.push_back(token);
        s.erase(0, pos + delimiter.length());
    }
    tokens.push_back(s);

    return tokens;
}

std::string s = "scott>=tiger>=mushroom";
std::string delimiter = ">=";

split(s, delimiter); // ["scott", "tiger", "mushroom"]

You can use the std::string::find() function to find the position of your string delimiter, then use std::string::substr() to get a token.

Example:

std::string s = "scott>=tiger";
std::string delimiter = ">=";
std::string token = s.substr(0, s.find(delimiter)); // token is "scott"
  • The find(const string& str, size_t pos = 0) function returns the position of the first occurrence of str in the string, or npos if the string is not found.

  • The substr(size_t pos = 0, size_t n = npos) function returns a substring of the object, starting at position pos and of length npos.


If you have multiple delimiters, after you have extracted one token, you can remove it (delimiter included) to proceed with subsequent extractions (if you want to preserve the original string, just use s = s.substr(pos + delimiter.length());):

s.erase(0, s.find(delimiter) + delimiter.length());

This way you can easily loop to get each token.

Complete Example

std::vector<std::string> split(const std::string& s, const std::string& delimiter) {
    std::vector<std::string> tokens;
    size_t pos = 0;
    std::string token;
    while ((pos = s.find(delimiter)) != std::string::npos) {
        token = s.substr(0, pos);
        tokens.push_back(token);
        s.erase(0, pos + delimiter.length());
    }
    tokens.push_back(s);

    return tokens;
}

std::string s = "scott>=tiger>=mushroom";
std::string delimiter = ">=";

split(s, delimiter); // ["scott", "tiger", "mushroom"]
对你的占有欲 2025-01-29 00:18:18

对于字符串定界符

基于A 字符串定界符的拆分字符串。例如,划分字符串“ adsf-+qwret-+nvfkbdsj--+orthdfjgh--+dfjrleih” 基于字符串分隔符 code>“ - +” ,输出将为> { adsf“,” qwret,“ nvfkbdsj”,“ orthdfjgh”,“ dfjrleih”}

#include <iostream>
#include <sstream>
#include <vector>

// for string delimiter
std::vector<std::string> split(std::string s, std::string delimiter) {
    size_t pos_start = 0, pos_end, delim_len = delimiter.length();
    std::string token;
    std::vector<std::string> res;

    while ((pos_end = s.find(delimiter, pos_start)) != std::string::npos) {
        token = s.substr (pos_start, pos_end - pos_start);
        pos_start = pos_end + delim_len;
        res.push_back (token);
    }

    res.push_back (s.substr (pos_start));
    return res;
}

int main() {
    std::string str = "adsf-+qwret-+nvfkbdsj-+orthdfjgh-+dfjrleih";
    std::string delimiter = "-+";
    std::vector<std::string> v = split (str, delimiter);

    for (auto i : v) cout << i << endl;

    return 0;
}

**Output**

adsf
qwret
nvfkbdsj
orthdfjgh
dfjrleih

对于单个字符定界符

基于字符定界符的拆分字符串。例如,将字符串拆分为“ adsf+qwer+poui+fdgh” with DeLimiter “+” 将输出 {“ adsf”,“ qwer”,“ qwer”,“ poui”,“ poui” ,“ fdgh”}

#include <iostream>
#include <sstream>
#include <vector>

std::vector<std::string> split (const std::string &s, char delim) {
    std::vector<std::string> result;
    std::stringstream ss (s);
    std::string item;

    while (getline (ss, item, delim)) {
        result.push_back (item);
    }

    return result;
}

int main() {
    std::string str = "adsf+qwer+poui+fdgh";
    std::vector<std::string> v = split (str, '+');

    for (auto i : v) cout << i << endl;

    return 0;
}

**Output**

adsf
qwer
poui
fdgh

For string delimiter

Split string based on a string delimiter. Such as splitting string "adsf-+qwret-+nvfkbdsj-+orthdfjgh-+dfjrleih" based on string delimiter "-+", output will be {"adsf", "qwret", "nvfkbdsj", "orthdfjgh", "dfjrleih"}

#include <iostream>
#include <sstream>
#include <vector>

// for string delimiter
std::vector<std::string> split(std::string s, std::string delimiter) {
    size_t pos_start = 0, pos_end, delim_len = delimiter.length();
    std::string token;
    std::vector<std::string> res;

    while ((pos_end = s.find(delimiter, pos_start)) != std::string::npos) {
        token = s.substr (pos_start, pos_end - pos_start);
        pos_start = pos_end + delim_len;
        res.push_back (token);
    }

    res.push_back (s.substr (pos_start));
    return res;
}

int main() {
    std::string str = "adsf-+qwret-+nvfkbdsj-+orthdfjgh-+dfjrleih";
    std::string delimiter = "-+";
    std::vector<std::string> v = split (str, delimiter);

    for (auto i : v) cout << i << endl;

    return 0;
}

**Output**

adsf
qwret
nvfkbdsj
orthdfjgh
dfjrleih

For single character delimiter

Split string based on a character delimiter. For example, splitting string "adsf+qwer+poui+fdgh" with delimiter "+" will output {"adsf", "qwer", "poui", "fdgh"}

#include <iostream>
#include <sstream>
#include <vector>

std::vector<std::string> split (const std::string &s, char delim) {
    std::vector<std::string> result;
    std::stringstream ss (s);
    std::string item;

    while (getline (ss, item, delim)) {
        result.push_back (item);
    }

    return result;
}

int main() {
    std::string str = "adsf+qwer+poui+fdgh";
    std::vector<std::string> v = split (str, '+');

    for (auto i : v) cout << i << endl;

    return 0;
}

**Output**

adsf
qwer
poui
fdgh
简美 2025-01-29 00:18:18

此方法使用 std :: String :: find 在不突变原始字符串的情况下通过记住上一个子字符串令牌的开始和结尾。

#include <iostream>
#include <string>

int main()
{
    std::string s = "scott>=tiger";
    std::string delim = ">=";

    auto start = 0U;
    auto end = s.find(delim);
    while (end != std::string::npos)
    {
        std::cout << s.substr(start, end - start) << std::endl;
        start = end + delim.length();
        end = s.find(delim, start);
    }

    std::cout << s.substr(start, end);
}

This method uses std::string::find without mutating the original string by remembering the beginning and end of the previous substring token.

#include <iostream>
#include <string>

int main()
{
    std::string s = "scott>=tiger";
    std::string delim = ">=";

    auto start = 0U;
    auto end = s.find(delim);
    while (end != std::string::npos)
    {
        std::cout << s.substr(start, end - start) << std::endl;
        start = end + delim.length();
        end = s.find(delim, start);
    }

    std::cout << s.substr(start, end);
}
幸福%小乖 2025-01-29 00:18:18

您可以使用下一个函数拆分字符串:

vector<string> split(const string& str, const string& delim)
{
    vector<string> tokens;
    size_t prev = 0, pos = 0;
    do
    {
        pos = str.find(delim, prev);
        if (pos == string::npos) pos = str.length();
        string token = str.substr(prev, pos-prev);
        if (!token.empty()) tokens.push_back(token);
        prev = pos + delim.length();
    }
    while (pos < str.length() && prev < str.length());
    return tokens;
}

You can use next function to split string:

vector<string> split(const string& str, const string& delim)
{
    vector<string> tokens;
    size_t prev = 0, pos = 0;
    do
    {
        pos = str.find(delim, prev);
        if (pos == string::npos) pos = str.length();
        string token = str.substr(prev, pos-prev);
        if (!token.empty()) tokens.push_back(token);
        prev = pos + delim.length();
    }
    while (pos < str.length() && prev < str.length());
    return tokens;
}
红墙和绿瓦 2025-01-29 00:18:18

使用C ++ 20的一种方法:

#include <iostream>
#include <ranges>
#include <string_view>

int main()
{
    std::string hello = "text to be parsed";
    auto split = hello
        | std::ranges::views::split(' ')
        | std::ranges::views::transform([](auto&& str) { return std::string_view(&*str.begin(), std::ranges::distance(str)); });

    for (auto&& word : split)
    {
        std::cout << word << std::endl;
    }
}

请参阅:
https://stackoverflow.com/a/48403210/10771848

https://en.cppreference.com/w/cpp/ranges/split_view

A way of doing it with C++20:

#include <iostream>
#include <ranges>
#include <string_view>

int main()
{
    std::string hello = "text to be parsed";
    auto split = hello
        | std::ranges::views::split(' ')
        | std::ranges::views::transform([](auto&& str) { return std::string_view(&*str.begin(), std::ranges::distance(str)); });

    for (auto&& word : split)
    {
        std::cout << word << std::endl;
    }
}

See:
https://stackoverflow.com/a/48403210/10771848
https://en.cppreference.com/w/cpp/ranges/split_view

智商已欠费 2025-01-29 00:18:18

您还可以为此使用Regex:

std::vector<std::string> split(const std::string str, const std::string regex_str)
{
    std::regex regexz(regex_str);
    std::vector<std::string> list(std::sregex_token_iterator(str.begin(), str.end(), regexz, -1),
                                  std::sregex_token_iterator());
    return list;
}

等效于:

std::vector<std::string> split(const std::string str, const std::string regex_str)
{
    std::sregex_token_iterator token_iter(str.begin(), str.end(), regexz, -1);
    std::sregex_token_iterator end;
    std::vector<std::string> list;
    while (token_iter != end)
    {
        list.emplace_back(*token_iter++);
    }
    return list;
}

并像这样使用:

#include <iostream>
#include <string>
#include <regex>

std::vector<std::string> split(const std::string str,
                               const std::string regex_str) {
    std::regex regexz(regex_str);
    return {std::sregex_token_iterator(str.begin(), str.end(), regexz, -1),
            std::sregex_token_iterator()};
}

int main()
{
    std::string input_str = "lets split this";
    std::string regex_str = " "; 
    auto tokens = split(input_str, regex_str);
    for (auto& item: tokens)
    {
        std::cout<<item <<std::endl;
    }
}

在线玩!

您可以简单地使用subsin,字符等,例如正常等,或使用实际的正则表达式进行分裂。

它也简洁,C ++ 11!

You can also use regex for this:

std::vector<std::string> split(const std::string str, const std::string regex_str)
{
    std::regex regexz(regex_str);
    std::vector<std::string> list(std::sregex_token_iterator(str.begin(), str.end(), regexz, -1),
                                  std::sregex_token_iterator());
    return list;
}

which is equivalent to :

std::vector<std::string> split(const std::string str, const std::string regex_str)
{
    std::sregex_token_iterator token_iter(str.begin(), str.end(), regexz, -1);
    std::sregex_token_iterator end;
    std::vector<std::string> list;
    while (token_iter != end)
    {
        list.emplace_back(*token_iter++);
    }
    return list;
}

and use it like this :

#include <iostream>
#include <string>
#include <regex>

std::vector<std::string> split(const std::string str,
                               const std::string regex_str) {
    std::regex regexz(regex_str);
    return {std::sregex_token_iterator(str.begin(), str.end(), regexz, -1),
            std::sregex_token_iterator()};
}

int main()
{
    std::string input_str = "lets split this";
    std::string regex_str = " "; 
    auto tokens = split(input_str, regex_str);
    for (auto& item: tokens)
    {
        std::cout<<item <<std::endl;
    }
}

play with it online!

you can simply use substrings, characters, etc like normal, or use actual regular expressions to do the splitting.
its also concise and C++11!

难如初 2025-01-29 00:18:18

答案已经存在,但是选定的答案使用擦除功能,这是非常昂贵的,想想一些非常大的字符串(在MBS中)。因此,我使用以下功能。

vector<string> split(const string& str, const string& delim)
{
    vector<string> result;
    size_t start = 0;

    for (size_t found = str.find(delim); found != string::npos; found = str.find(delim, start))
    {
        result.emplace_back(str.begin() + start, str.begin() + found);
        start = found + delim.size();
    }
    if (start != str.size())
        result.emplace_back(str.begin() + start, str.end());
    return result;      
}

Answer is already there, but selected-answer uses erase function which is very costly, think of some very big string(in MBs). Therefore I use below function.

vector<string> split(const string& str, const string& delim)
{
    vector<string> result;
    size_t start = 0;

    for (size_t found = str.find(delim); found != string::npos; found = str.find(delim, start))
    {
        result.emplace_back(str.begin() + start, str.begin() + found);
        start = found + delim.size();
    }
    if (start != str.size())
        result.emplace_back(str.begin() + start, str.end());
    return result;      
}
心的憧憬 2025-01-29 00:18:18

该代码将线条从文本分配,然后将所有人添加到向量中。

vector<string> split(char *phrase, string delimiter){
    vector<string> list;
    string s = string(phrase);
    size_t pos = 0;
    string token;
    while ((pos = s.find(delimiter)) != string::npos) {
        token = s.substr(0, pos);
        list.push_back(token);
        s.erase(0, pos + delimiter.length());
    }
    list.push_back(s);
    return list;
}

称为:

vector<string> listFilesMax = split(buffer, "\n");

This code splits lines from text, and add everyone into a vector.

vector<string> split(char *phrase, string delimiter){
    vector<string> list;
    string s = string(phrase);
    size_t pos = 0;
    string token;
    while ((pos = s.find(delimiter)) != string::npos) {
        token = s.substr(0, pos);
        list.push_back(token);
        s.erase(0, pos + delimiter.length());
    }
    list.push_back(s);
    return list;
}

Called by:

vector<string> listFilesMax = split(buffer, "\n");
爱殇璃 2025-01-29 00:18:18

strtok 允许您以多个字符作为定界器传递。我敢打赌,如果您通过“&gt; =”您的示例字符串将正确拆分(即使&gt; and =被计为单个定界符)。

编辑如果您不想使用 c_str()将从字符串转换为char*,则可以使用 substr tokenize。

string token, mystring("scott>=tiger");
while(token != mystring){
  token = mystring.substr(0,mystring.find_first_of(">="));
  mystring = mystring.substr(mystring.find_first_of(">=") + 1);
  printf("%s ",token.c_str());
}

strtok allows you to pass in multiple chars as delimiters. I bet if you passed in ">=" your example string would be split correctly (even though the > and = are counted as individual delimiters).

EDIT if you don't want to use c_str() to convert from string to char*, you can use substr and find_first_of to tokenize.

string token, mystring("scott>=tiger");
while(token != mystring){
  token = mystring.substr(0,mystring.find_first_of(">="));
  mystring = mystring.substr(mystring.find_first_of(">=") + 1);
  printf("%s ",token.c_str());
}
你不是我要的菜∠ 2025-01-29 00:18:18

一种非常简单/幼稚的方法:

vector<string> words_seperate(string s){
    vector<string> ans;
    string w="";
    for(auto i:s){
        if(i==' '){
           ans.push_back(w);
           w="";
        }
        else{
           w+=i;
        }
    }
    ans.push_back(w);
    return ans;
}

或者您可以使用boost库拆分函数:

vector<string> result; 
boost::split(result, input, boost::is_any_of("\t"));

或者您可以尝试代币或strtok:

char str[] = "DELIMIT-ME-C++"; 
char *token = strtok(str, "-"); 
while (token) 
{ 
    cout<<token; 
    token = strtok(NULL, "-"); 
} 

或者您可以做到这一点:

char split_with=' ';
vector<string> words;
string token; 
stringstream ss(our_string);
while(getline(ss , token , split_with)) words.push_back(token);

A very simple/naive approach:

vector<string> words_seperate(string s){
    vector<string> ans;
    string w="";
    for(auto i:s){
        if(i==' '){
           ans.push_back(w);
           w="";
        }
        else{
           w+=i;
        }
    }
    ans.push_back(w);
    return ans;
}

Or you can use boost library split function:

vector<string> result; 
boost::split(result, input, boost::is_any_of("\t"));

Or You can try TOKEN or strtok:

char str[] = "DELIMIT-ME-C++"; 
char *token = strtok(str, "-"); 
while (token) 
{ 
    cout<<token; 
    token = strtok(NULL, "-"); 
} 

Or You can do this:

char split_with=' ';
vector<string> words;
string token; 
stringstream ss(our_string);
while(getline(ss , token , split_with)) words.push_back(token);
云淡月浅 2025-01-29 00:18:18

我将使用 boost :: tokenizer 。这里的文档说明了如何制作适当的引物函数:

这是适合您的情况的一种。

struct my_tokenizer_func
{
    template<typename It>
    bool operator()(It& next, It end, std::string & tok)
    {
        if (next == end)
            return false;
        char const * del = ">=";
        auto pos = std::search(next, end, del, del + 2);
        tok.assign(next, pos);
        next = pos;
        if (next != end)
            std::advance(next, 2);
        return true;
    }

    void reset() {}
};

int main()
{
    std::string to_be_parsed = "1) one>=2) two>=3) three>=4) four";
    for (auto i : boost::tokenizer<my_tokenizer_func>(to_be_parsed))
        std::cout << i << '\n';
}

I would use boost::tokenizer. Here's documentation explaining how to make an appropriate tokenizer function: http://www.boost.org/doc/libs/1_52_0/libs/tokenizer/tokenizerfunction.htm

Here's one that works for your case.

struct my_tokenizer_func
{
    template<typename It>
    bool operator()(It& next, It end, std::string & tok)
    {
        if (next == end)
            return false;
        char const * del = ">=";
        auto pos = std::search(next, end, del, del + 2);
        tok.assign(next, pos);
        next = pos;
        if (next != end)
            std::advance(next, 2);
        return true;
    }

    void reset() {}
};

int main()
{
    std::string to_be_parsed = "1) one>=2) two>=3) three>=4) four";
    for (auto i : boost::tokenizer<my_tokenizer_func>(to_be_parsed))
        std::cout << i << '\n';
}
开始看清了 2025-01-29 00:18:18

这应该适用于字符串(或单个字符)定界符。不要忘记包括 #include&lt; sstream&gt;

std::string input = "Alfa=,+Bravo=,+Charlie=,+Delta";
std::string delimiter = "=,+"; 
std::istringstream ss(input);
std::string token;
std::string::iterator it;

while(std::getline(ss, token, *(it = delimiter.begin()))) {
    std::cout << token << std::endl; // Token is extracted using '='
    it++;
    // Skip the rest of delimiter if exists ",+"
    while(it != delimiter.end() and ss.peek() == *(it)) { 
        it++; ss.get(); 
    }
}

第一个使用字符串定界符的第一个字符提取循环提取令牌。第二个循环跳过了其余的定界符,并在下一代币的开头停下来。

This should work perfectly for string (or single character) delimiters. Don't forget to include #include <sstream>.

std::string input = "Alfa=,+Bravo=,+Charlie=,+Delta";
std::string delimiter = "=,+"; 
std::istringstream ss(input);
std::string token;
std::string::iterator it;

while(std::getline(ss, token, *(it = delimiter.begin()))) {
    std::cout << token << std::endl; // Token is extracted using '='
    it++;
    // Skip the rest of delimiter if exists ",+"
    while(it != delimiter.end() and ss.peek() == *(it)) { 
        it++; ss.get(); 
    }
}

The first while loop extracts a token using the first character of the string delimiter. The second while loop skips the rest of the delimiter and stops at the beginning of the next token.

望喜 2025-01-29 00:18:18

以防万一将来,某人想要 vincenzo pii 的答案

#include <vector>
#include <string>


std::vector<std::string> SplitString(
    std::string str,
    std::string delimeter)
{
    std::vector<std::string> splittedStrings = {};
    size_t pos = 0;

    while ((pos = str.find(delimeter)) != std::string::npos)
    {
        std::string token = str.substr(0, pos);
        if (token.length() > 0)
            splittedStrings.push_back(token);
        str.erase(0, pos + delimeter.length());
    }

    if (str.length() > 0)
        splittedStrings.push_back(str);
    return splittedStrings;
}

, bugs,以便该函数在开始或字符串的末尾有分界符,则不会返回空字符串

Just in case in the future, someone wants out of the box function of Vincenzo Pii 's answer

#include <vector>
#include <string>


std::vector<std::string> SplitString(
    std::string str,
    std::string delimeter)
{
    std::vector<std::string> splittedStrings = {};
    size_t pos = 0;

    while ((pos = str.find(delimeter)) != std::string::npos)
    {
        std::string token = str.substr(0, pos);
        if (token.length() > 0)
            splittedStrings.push_back(token);
        str.erase(0, pos + delimeter.length());
    }

    if (str.length() > 0)
        splittedStrings.push_back(str);
    return splittedStrings;
}

I also fixed some bugs so that the function won't return an empty string if there is a delimiter at the start or the end of the string

淡看悲欢离合 2025-01-29 00:18:18

这是我对此的看法。它处理边缘情况并采用可选参数以从结果中删除空条目。

bool endsWith(const std::string& s, const std::string& suffix)
{
    return s.size() >= suffix.size() &&
           s.substr(s.size() - suffix.size()) == suffix;
}

std::vector<std::string> split(const std::string& s, const std::string& delimiter, const bool removeEmptyEntries = false)
{
    std::vector<std::string> tokens;

    for (size_t start = 0, end; start < s.length(); start = end + delimiter.length())
    {
         size_t position = s.find(delimiter, start);
         end = position != std::string::npos ? position : s.length();

         std::string token = s.substr(start, end - start);
         if (!removeEmptyEntries || !token.empty())
         {
             tokens.push_back(token);
         }
    }

    if (!removeEmptyEntries &&
        (s.empty() || endsWith(s, delimiter)))
    {
        tokens.push_back("");
    }

    return tokens;
}

例子

split("a-b-c", "-"); // [3]("a","b","c")

split("a--c", "-"); // [3]("a","","c")

split("-b-", "-"); // [3]("","b","")

split("--c--", "-"); // [5]("","","c","","")

split("--c--", "-", true); // [1]("c")

split("a", "-"); // [1]("a")

split("", "-"); // [1]("")

split("", "-", true); // [0]()

Here's my take on this. It handles the edge cases and takes an optional parameter to remove empty entries from the results.

bool endsWith(const std::string& s, const std::string& suffix)
{
    return s.size() >= suffix.size() &&
           s.substr(s.size() - suffix.size()) == suffix;
}

std::vector<std::string> split(const std::string& s, const std::string& delimiter, const bool removeEmptyEntries = false)
{
    std::vector<std::string> tokens;

    for (size_t start = 0, end; start < s.length(); start = end + delimiter.length())
    {
         size_t position = s.find(delimiter, start);
         end = position != std::string::npos ? position : s.length();

         std::string token = s.substr(start, end - start);
         if (!removeEmptyEntries || !token.empty())
         {
             tokens.push_back(token);
         }
    }

    if (!removeEmptyEntries &&
        (s.empty() || endsWith(s, delimiter)))
    {
        tokens.push_back("");
    }

    return tokens;
}

Examples

split("a-b-c", "-"); // [3]("a","b","c")

split("a--c", "-"); // [3]("a","","c")

split("-b-", "-"); // [3]("","b","")

split("--c--", "-"); // [5]("","","c","","")

split("--c--", "-", true); // [1]("c")

split("a", "-"); // [1]("a")

split("", "-"); // [1]("")

split("", "-", true); // [0]()
倾其所爱 2025-01-29 00:18:18

这类似于其他答案,但使用 String_view 。因此,这些只是原始字符串的视图。类似于C ++ 20示例。尽管这将是C ++ 17示例。 (编辑到跳动空匹配)

#include <algorithm>
#include <iostream>
#include <string_view>
#include <vector>
std::vector<std::string_view> split(std::string_view buffer,
                                    const std::string_view delimeter = " ") {
  std::vector<std::string_view> ret{};
  std::decay_t<decltype(std::string_view::npos)> pos{};
  while ((pos = buffer.find(delimeter)) != std::string_view::npos) {
    const auto match = buffer.substr(0, pos);
    if (!match.empty()) ret.push_back(match);
    buffer = buffer.substr(pos + delimeter.size());
  }
  if (!buffer.empty()) ret.push_back(buffer);
  return ret;
}
int main() {
  const auto split_values = split("1 2 3 4 5 6 7 8 9     10 ");
  std::for_each(split_values.begin(), split_values.end(),
                [](const auto& str) { std::cout << str << '\n'; });
  return split_values.size();
}

This is similar to other answers but it's using string_view. So these are just views for the original string. Similar to the c++20 example. Though this would be a c++17 example. (edit to skip empty matches)

#include <algorithm>
#include <iostream>
#include <string_view>
#include <vector>
std::vector<std::string_view> split(std::string_view buffer,
                                    const std::string_view delimeter = " ") {
  std::vector<std::string_view> ret{};
  std::decay_t<decltype(std::string_view::npos)> pos{};
  while ((pos = buffer.find(delimeter)) != std::string_view::npos) {
    const auto match = buffer.substr(0, pos);
    if (!match.empty()) ret.push_back(match);
    buffer = buffer.substr(pos + delimeter.size());
  }
  if (!buffer.empty()) ret.push_back(buffer);
  return ret;
}
int main() {
  const auto split_values = split("1 2 3 4 5 6 7 8 9     10 ");
  std::for_each(split_values.begin(), split_values.end(),
                [](const auto& str) { std::cout << str << '\n'; });
  return split_values.size();
}
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