我正在尝试将s1内的所有字符更改为“ x”。 但是，当我运行代码时，编译器仅打印了11次“ hello world”

Question

I'm new to C++. I'm trying to change all character within s1 to 'x'. When I run the code, however, the compiler just printed out 'hello world' 11 times. Why is this happening?

int main(){

    string s1 = "hello world";

    for (auto &c : s1){
        s1[c] = 'x';
        cout << s1 << endl;
    }


    return 0;
}

Answer 1

In the for loop you are using, c is actually holding different characters of the string s1 not the index of each element in s1.

for (auto &c : s1)

To actually change each characters of the string use below for loop:

for (int c = 0; c < s1.size(); ++c)