String comparison using '==' vs. 'strcmp()'

The reason to use it is because strcmp

returns < 0 if str1 is less than str2; > 0 if str1 is greater than str2, and 0 if they are equal.

=== only returns true or false, it doesn't tell you which is the "greater" string.

You should never use == for string comparison. === is OK.

$something = 0;
echo ('password123' == $something) ? 'true' : 'false';

Just run the above code and you'll see why.

$something = 0;
echo ('password123' === $something) ? 'true' : 'false';

Now, that's a little better.

Don't use == in PHP. It will not do what you expect. Even if you are comparing strings to strings, PHP will implicitly cast them to floats and do a numerical comparison if they appear numerical.

For example '1e3' == '1000' returns true. You should use === instead.