C++ 用for/while循环实现字符串逆置输出

1.for循环实现字符串逆置
#include <iostream>
using namespace std;
int main() {
    string str;
    
    cout << "请输入一个字符串：" << endl;
    cin >> str;

    int j = str.length() - 1;  //必须要放在输入字符串之后
    for (int i = 0; i < j; i++) {
        int tmp = str[i];
        str[i] = str[j];
        str[j] = tmp;
        j--;
    }
    cout << str << endl;
    system("pause");
    return 0;
}
2.while循环实现字符串逆置
#include <iostream>
#include <stdio.h>
using namespace std;
int main() {
    string str;
    int i = 0;
    char tmp;

    cout << "请输入一个字符串：" << endl;
    cin >> str;

    int j = str.length() - 1;
    while (i < j) {
        tmp = str[i];
        str[i] = str[j];
        str[j] = tmp;
        i++;
        j--;
    }

    cout << str << endl;
    system("pause");
    return 0;
}