非常简单的 c++ 中的 lnk2019 错误程序

Question

我尝试过删除各种部件并进行构建，但没有任何方法可以使 lnk2019 错误消失，甚至不会产生任何正常错误。

目前所有内容都在一个文件中（完成后不会更晚）。该程序具有三个单词列表，并从中创建一个行话短语，您应该能够添加单词、删除单词、查看列表、恢复默认值、保存对文件的更改以及从文件加载更改。

#include "stdafx.h"
#include <iostream>
#include <string.h>

using namespace std;

const int maxlist = 20;

string adj1[maxlist], adj2[maxlist], noun[maxlist];

void defaultlist(int list)
{
 if(list == 1)
 {
  adj1[0] = "green";
  adj1[1] = "red";
  adj1[2] = "yellow";
  adj1[3] = "blue";
  adj1[4] = "purple";

  int i = 5;
  while(i != maxlist)
  {
   adj1[i] = "";
   i = i + 1;
  }
 }

 if(list == 2)
 {
  adj2[0] = "shiny";
  adj2[1] = "hard";
  adj2[2] = "soft";
  adj2[3] = "spiky";
  adj2[4] = "furry";

  int i = 5;
  while(i != maxlist)
  {
   adj2[i] = "";
   i = i + 1;
  }
 }

 if(list == 3)
 {
  noun[0] = "cat";
  noun[1] = "dog";
  noun[2] = "desk";
  noun[3] = "chair";
  noun[4] = "door";

  int i = 5;
  while(i != maxlist)
  {
   noun[i] = "";
   i = i + 1;
  }
 }
return;
}


void printlist(int list)
{
 if(list == 1)
 {
  int i = 0;
  while(!(i == maxlist))
  {
   cout << adj1[i] << endl;
   i = i + 1;
  }
 }

 if(list == 2)
 {
  int i = 0;
  while(!(i == maxlist))
  {
   cout << adj2[i] << endl;
   i = i + 1;
  }
 }

 if(list == 3)
 {
  int i = 0;
  while(!(i == maxlist))
  {
   cout << noun[i] << endl;
   i = i + 1;
  }
 }
return;
}

string makephrase()
{
 int num1 = rand()%maxlist;
 int num2 = rand()%maxlist;
 int num3 = rand()%maxlist;
 int num4 = rand()%1;

 string word1, word2, word3;

 if(num4 = 0)
 {
  word1 = adj1[num1];
  word2 = adj2[num2];
 }
 else
 {
  word1 = adj2[num1];
  word2 = adj1[num2];
 }

 word3 = noun[num3];

return word1 + " ," + word2 + " " + word3;
}

string addword(string word, int list)
{
 string result;

 if(list == 1)
 {
  int i = 0;
  while(!(adj1[i] == "" || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "List is full. Please try again.";
  if(adj1[i] == "")
  {
   adj1[i] = word;
   result = "Word was entered successfully.";
  }
 }

 if(list == 2)
 {
  int i = 0;
  while(!(adj2[i] == "" || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "List is full. Please try again.";
  if(adj2[i] == "")
  {
   adj2[i] = word;
   result = "Word was entered successfully.";
  }
 } 

 if(list == 3)
 {
  int i = 0;
  while(!(noun[i] == "" || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "List is full. Please try again.";
  if(noun[i] == "")
  {
   noun[i] = word;
   result = "Word was entered successfully.";
  }
 }
return result;
}
string removeword(string word, int list)
{
 string result;

 if(list == 1)
 {
  int i = 0;
  while(!(adj1[i] == word || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "Word is not on the list. Please try again.";
  if(adj1[i] == word)
  {
   adj1[i] = "";
   result = "Word was removed successfully.";
  }
 }

  if(list == 2)
 {
  int i = 0;
  while(!(adj2[i] == word || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "Word is not on the list. Please try again.";
  if(adj2[i] == word)
  {
   adj2[i] = "";
   result = "Word was removed successfully.";
  }
 }

 if(list == 3)
 {
  int i = 0;
  while(!(noun[i] == word || i == maxlist))
  {
   i = i + 1;
  }

  if(i == maxlist) result = "Word is not on the list. Please try again.";
  if(noun[i] == word)
  {
   noun[i] = "";
   result = "Word was removed successfully.";
  }
 }

return result;
}



/////////////////////////////main///////////////////////////////////


int main()
{
 string mainselection;
 string makeselection;
 string phrase;

 defaultlist(1);
 defaultlist(2);
 defaultlist(3);

 cout << "This program generates jargon phrases made of two adjectives and one noun,";
 cout << " on three lists. Each list may contain a maximum of " << maxlist << "elements.";
 cout << " Please choose from the following menu by typing the appropriate number ";
 cout << "and pressing enter." << endl;

 cout << endl;

 cout << "1. Make a jargon phrase." << endl;
 cout << "2. View a list." << endl;
 cout << "3. Add a word to a list." << endl;
 cout << "4. Remove a word from a list." << endl;
 cout << "5. Restore default lists." << endl;
 cout << "More options coming soon!." << endl;

 cin >> mainselection

 if(mainselection == 1)
 {
  phrase = makephrase();

  cout << "Your phrase is " << phrase << "." << endl;
  cout << "To make another phrase, press 1. To go back to the main menu,";
  cout << " press 2. To exit the program, press 3." << endl;

  cin >> makeselection;

  while(!(makeselection == "1" || makeselection == "2" || makeselection == "3"))
  {
   cout << "You have entered an invalid selection. Please try again." << endl;
   cin >> makeselection;
  }

  while(makeselection == "1")
  {
   phrase = makephrase();
   cout << "To make another phrase, press 1. To go back to the main menu,";
   cout << " press 2. To exit the program, press 3." << endl;
  }

  if(makeselection == "2") main();
  if(makeselection == "3") return 0;
 }

return 0;
}

//Rest of the options coming soon!

Answer 1

根据 gcc 的问题是，您尚未声明 rand() 函数的正确包含 - 我添加了 #include 然后问题就消失了。

我还应该补充一点，在您的主要功能中，您已经完成了以下操作：

cin >> mainselection;
if ( mainselection == 1 )

这不起作用。 Mainselection 是一个字符串，只能使用类比较方法进行比较，如下所示：

cin >> mainselection;
if ( mainselection.compare("1") )

如果相等，则返回 0。

另外，如果您使用 std::vector ，您可以在 C++ 中非常轻松地动态调整大小的数组，只需不断地将项目推到向量的后面即可。这意味着您不需要对限制进行硬编码。

Answer 2

一些可以帮助您的建议：

• 第 107 行：if(num4 = 0)（赋值运算符）应为 if(num4 == 0)（等于运算符）。
• 第 260 行：cin >> 后面缺少一个分号主要选择。
• 第 261 行：if(mainselection == 1) 是非法的，mainselection 是 std::string。
• 第 284 行： if(makeselection == "2") main(); 不允许在 C++ 中递归调用 main() 函数。