Difference Between $a = 0 and $a = '0' in PHP

Question

I had an if statement similar to the following in my code and it took me forever to figure out what the problem was.

$a = 0;
if($a == 'something')
 {
 //this was being output when I didn't want it to be
 }

Using

$a = '0'; 

fixed it, but I don't really know what's going on here.

Answer 1

One's a string, one's an integer. PHP will translate between the two as needed, unless you're using the 'strict' operators:

(0 == '0') // true
(0 === '0') // false (types don't match).

In your case, you'r comparing an integer 0 to a string 'something'. PHP will convert the string 'something' to an integer. If there's no digits in there at all, it'll conver to an integer 0, which makes your comparison true.

Answer 2

Just a guess, but I assume it's trying to cast the string to an integer.

intval('something') I expect will return 0.