使用getline后如何使cin工作? [英] How to make cin work after using getline?

问题描述

因此，我使用cin.getline(str，10，'h')读取了一个字符串，如您所见，我使用了一个自定义定界符'h'，并且希望最多读取9个字符.完成此操作后，我使用cin >> n将整数读入我的int变量n.

So, I read a string using cin.getline(str,10,'h') where as you can see I have used a custom delimiter 'h' and want to read a maximum of 9 characters. After doing this, I use cin>>n to read an integer into my int variable n.

#include <iostream>
using namespace std;
int main() {
    int n;
    char str[100];
    cin.getline(str, 10, 'h');
    cout<<str<<'-'<<endl;
    cout<<"Enter a number:";
    cin>>n;
    cout<<n;
    return 0;
}

假设我传递了以下输入

2 3   pl32

这是一个'\ n'，后跟"2 3 pl32".我希望getline读取字符串"\ n2 3 pl" ，然后cin读取整数32.但这不是发生的情况.

which is a '\n' followed by "2 3 pl32". I expect getline to read the string "\n2 3 pl" and then cin to read the integer 32. But that's isn't what happened.

实际输出显示cin读取了垃圾值:

The actual output showed that the cin read garbage value:

2 3   pl-
Enter a number:0

好的，我现在明白了.Getline设置了 failbit ，这就是导致此问题的原因.问题解决了.

Ok, so I get it now. Getline set the failbit , that's what caused the issue. Problem solved.

推荐答案

问题是 getline 找不到其定界符，并且已在 cin 中设置了故障位标志.您必须清除该标志才能在流上再次读取:

The problem is that getline has not found its delimiter, and has set the failbit flag in cin. You must clear the flag to read again on the stream:

...
cin.getline(str, 10, 'h');
cin.clear();                  # reset a possible error condition
cout<<str<<'-'<<endl;
cout<<"Enter a number:";
cin>>n;
...

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