C++string比较是否相同

你可以使用C++中的`std::string`类提供的`compare()`函数进行字符串比较，该函数会返回一个整数，表示两个字符串的比较结果。如果返回值为0，则表示两个字符串相同。下面是一个示例代码：

#include <iostream>
#include <string>

int main() {
    std::string str1 = "hello";
    std::string str2 = "world";
    std::string str3 = "hello";

    int result1 = str1.compare(str2);
    int result2 = str1.compare(str3);

    if (result1 == 0) {
        std::cout << "str1 is equal to str2" << std::endl;
    } else {
        std::cout << "str1 is not equal to str2" << std::endl;
    }

    if (result2 == 0) {
        std::cout << "str1 is equal to str3" << std::endl;
    } else {
        std::cout << "str1 is not equal to str3" << std::endl;
    }

    return 0;
}

输出结果：

str1 is not equal to str2
str1 is equal to str3