程序跳过 Getline() 而不接受用户输入

Question

这是一个很奇怪的问题，当我的程序询问用户地址时，不是等待输入，而是跳过 getline() 函数完全

Answerinput:

cout << "would you like to add another entry to the archive? (Y/N):";

cin >> answer;

cout << endl;
cout << endl;

answer = toupper(answer);


 switch(answer)
    {
    case 'Y':
        Entrynumber++;

        cout << "began record number " << Entrynumber << "+ 1." << endl;

        cout << "Enter the last name of the person to be entered" << endl;

        cin >> stringentry;
        cout << endl;

        stringlength = stringentry.length();

        strcpy(Record[Entrynumber].Last_Name, stringentry.c_str());


        Record[Entrynumber].Last_Name[stringlength] = '*';



        cout << "Enter the first name of the person" << endl;

        cin >> stringentry;
        cout << endl;

        stringlength = stringentry.length();

        strcpy(Record[Entrynumber].First_Name, stringentry.c_str());

        Record[Entrynumber].First_Name[stringlength] = '*';

        cout << "Enter the SSN of the person" << endl;
        cin >> Record[Entrynumber].SSN;
        cout << endl;

        cout << "Enter the age of the person" << endl;
        cin >> Record[Entrynumber].Age;
        cout << endl;

        cout << "Enter the address of the person" << endl;


        cin.getline(Record[Entrynumber].Address,70);


        cout << endl;


        stringentry = Record[Entrynumber].Address;

        stringlength = stringentry.length();



        Record[Entrynumber].Address[stringlength] = '*';

        cout << "you entered:" << endl;



        for(jim = 0 ; Record[Entrynumber].Last_Name[jim + 1] != '*' ; jim++)
        {
            cout << Record[Entrynumber].Last_Name[jim];
        }

        cout << ',' ;


        for(jim = 0 ; Record[Entrynumber].First_Name[jim + 1] != '*' ; jim++)
        {
            cout << Record[Entrynumber].First_Name[jim];
        }

        cout << endl;

        cout << Record[Entrynumber].SSN << endl;
        cout << Record[Entrynumber].Age << endl;

        for(jim = 0 ; Record[Entrynumber].Address[jim + 1] != '*' ; jim++)
        {
            cout << Record[Entrynumber].Address[jim];
        }
        cout << endl;
        cout << endl;


        goto Answerinput;
    case 'N':
        cout << "ok" << endl;
        break;
    default:
        cout << "invalid answer" << endl;
        goto Answerinput;
    }

输出到控制台

would you like to add another entry to
the archive? (Y/N):Y

began record number 6+ 1. 


 Enter the last name of the person to be entered 
 John


 Enter the first name of the person 
 John

 Enter the SSN of the person  22222222

 Enter the age of the person  22

 Enter the address of the person

 you entered: 
Joh,Joh 
22222222 
22
 *¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦¦
 //////////////22 more lines of'|'//////////////////////////////////////////////
 ... 
¦¦¦¦¦¦¦¦l3-j

 would you like to add another entry to the archive? (Y/N):

cin.getline() 和 getline() 都做同样的事情。

我使用的是 MVC++ 2008。Record

数组中的所有字段都是结构，Record[Entrynumber].Address 是一个 char 数组。

Answer 1

Cin 可能会将回车符留在 getline 检索的缓冲区中。尝试

cin.ignore(1000, '\n');

cin.getline(Record[Entrynumber].Address,70);

一下>>运算符在检索数据后不会删除换行符，但会在检索数据之前忽略前导空格，而 getline 只是检索其中的内容，并在读取后删除 '\n'，因为它是它“获取”的行的一部分。

Answer 2

鉴于您的 getline 首先读取的缓冲区中可能会残留输入，我建议您在尝试输入下一个数据之前清除缓冲区：

std::cin.ignore(std::numeric_limits<std::streamsize>::max(),'\n');