string字符串比较c++

在C++中，可以使用比较运算符（==、!=、<、>、<=、>=）来比较两个字符串。字符串的比较规则是按顺序先从前往后比较，同序号的字符按照ASCII码值比较，直到遇到对应字符不等或者字符串结束。例如：

#include <iostream>
#include <string>
using namespace std;

int main() {
    string str1 = "hello";
    string str2 = "world";
    string str3 = "hello";
    if (str1 == str2) {
        cout << "str1 is equal to str2" << endl;
    } else {
        cout << "str1 is not equal to str2" << endl;
    }
    if (str1 == str3) {
        cout << "str1 is equal to str3" << endl;
    } else {
        cout << "str1 is not equal to str3" << endl;
    }
    if (str1 < str2) {
        cout << "str1 is less than str2" << endl;
    } else {
        cout << "str1 is not less than str2" << endl;
    }
    return 0;
}

输出结果为：

str1 is not equal to str2
str1 is equal to str3
str1 is less than str2