Parse == and === (double equal sign, triple equal sign) in php

if($config['urlrewrite']==1)
 or
if($config['urlrewrite']==='1')
 to judge.

Instructions: $a == $b;// Equal TRUE if $a is equal to $b. $a === $b;// Identical TRUE if $a is equal to $b, and they are of the same type. (introduced in PHP 4) means: == does not determine whether the two are of the same data type, while === is a more strict comparison. It not only requires that the two values ​​​​are equal, but also requires that their data types are also the same.