Differences between compare and == for std::string [duplicate]

Question

I am getting different results when using == or std::string::compare between two strings.

This is the code I am executing.

#include <iostream>
#include <string>

int main()
{
    std::string str1 = "W";
    char tmpChar = 'W';
    std::string str2(1, tmpChar);
    
    bool equalCompare = str1.compare(str2);
    bool equalSign = (str1 == str2);
    std::cout << "Compare result: " << equalCompare << std::endl;
    std::cout << "Equal sign result: " << equalSign << std::endl;
    
    return 0;
}

I guess it has to do with how I am creating str2, but that is the way I found out to convert a single char to a string.

I saw that post and I thought that they should be equal. eeroika answer is right. compare return an int and I thought it was a bool. The difference is in the casting — Wirlous
– Wirlous, Commented Sep 15, 2021 at 14:04

eerorika · Accepted Answer · 2021-09-15 14:00:47Z

2

Differences between compare and == for std::string

The difference is in what they return. == returns true when the strings compare equal and false otherwise. compare returns negative integer when *this is before the argument, zero when strings are equal, and positive integer when the argument is before *this.

edited Sep 15, 2021 at 14:00

answered Sep 15, 2021 at 13:58

eerorika

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