PHP type matching

Question

In PHP, can someone explain to me why this resolves to true:

'NONE' == 0

Answer 1

Because the string is 0 when evaluated in a number context. Quoting:

If you compare a number with a string or the comparison involves numerical strings, then each string is converted to a number and the comparison performed numerically.

So it depends on what the string contains.

Also, see the chapter on Type Juggling and Type Comparison in the PHP Manual.

Answer 2

Because any non-numerical string cast to int will turn into 0.

If you don't want that to happen, use ===, the identical operator.

Read:
http://php.net/manual/en/language.operators.comparison.php
http://php.net/manual/en/types.comparisons.php