c++ - 限制一组内的字符串长度？

Question

我必须编写一个程序，允许用户输入最多 20 个名称，每个名称最多 40 个字符。

当我在不尝试以任何方式限制字符串长度的情况下编写代码时，它起作用了。但是当我尝试使用 if/else 语句限制字符串长度时，它不起作用。我对 C++ 很陌生，所以它真的是在黑暗中拍摄。我做错了什么？

#include <iostream>
#include <string>
#include <set>
#include <algorithm>

using namespace std;

void print(const string& name) {
    cout << name << endl;
}

int main() {
    set<string> ListOfNames;
    cout << "Please enter up to 20 names of up to 40 characters each below:     " << endl;
for (int i = 1; i <= 20; ++i) {
    string name;
    cout << i << ". ";
    getline(cin, name);
    if (name.size() >= 40) {
        ListOfNames.insert(name);
    }
    else break;
    cerr << "You entered more than 40 characters. Please try again.";
}

for_each(ListOfNames.begin(), ListOfNames.end(), &print);
return 0;

}

输出:

1. (user inputs name here)
press any key to continue...

编辑代码:

#include <iostream>
#include <string>
#include <set>
#include <algorithm>

using namespace std;

void print(const string& name) {
    cout << name << endl;
}

int main() {
    set<string> ListOfNames;
    cout << "Please enter up to 20 names of up to 40 characters each below:         " << endl;
for (int i = 1; i <= 20; ++i) {
    string name;
    cout << i << ". ";
    getline(cin, name);
    if (name.size() <= 40) {
        ListOfNames.insert(name);
    }
    else
    {
        cerr << "You entered more than 40 characters. Please try again.";
        break;
    }

    for_each(ListOfNames.begin(), ListOfNames.end(), &print);
    return 0;
    }
}

Answer 1

你好像说只有当字符串大于 40 且不小于 40 时才运行代码