strpos returning false is not buggy?

[johnmerlino1]

I find it a bit buggy that strpos returns false instead of -1.

 

The equivalent C implementation returns -1:

int strpos(char s[], char t[])
{
    int i, j, k;

    for (i = 0; s[i] != '\0'; i++) {
        for (j=i, k=0; t[k]!='\0' && s[j]==t[k]; j++, k++)
            ;

        if (k > 0 && t[k] == '\0')
            return i;
    }

    return -1;
}

The problem with returning false is that false can also evaluate to 0 which can also happen to be the first index of a match. Therefore, you have a hard to find bug. I know that you can use the identity operator to check for falseness: ===. But wouldn't it be a better design for the function to just return -1?

[trq]

This is one of php's little quirks, there is no way to fix it now without breaking BC. Live with it.

[requinix]

C returns -1 because it can't return a mixed boolean/integer (putting aside the fact that it doesn't have actual booleans in the first place). PHP can so it returns false.

 

Frankly I'd rather it returns false: I see false == 0 being a better situation than -1 == true.