PHP is_null() and ==null [duplicate]

In PHP, what is the difference between is_null and ==null in PHP? What are the qualifications for both to return true?

Solution 1:

is_null is the same as === null. Both return true when a variable is null (or unset).

Note that I'm using === and not ==. === compares type as well as value.

Solution 2:

So you can understand it better:

$a = null;
$b = 0;

is_null($a) // TRUE
$a == null  // TRUE
$a === null // TRUE
is_null($b) // FALSE
$b == null  // TRUE
$b === null // FALSE

Solution 3:

There are a couple really good charts on the php.net site that show how different values react:

Type Comparison - php.net

Solution 4:

You can check the comparison between is_null() and null === $var

Good comparison between two