Question

Possible Duplicate:
is_null($x) vs $x === null in PHP

In the following context !== null, !is_null() and isset() all produce the same result:

$foo = null;

function foo() {
    if ($this->foo !== null) {
        ...
    }
    if (!is_null($this->foo)) {
        ...
    }
    if (isset($this->foo)) {
        ...
    }
}

Which one is the quickest and which would you recommend in that context?

Answer 1

If you’re not sure that the variable exists, use isset.

Example:

$content = (isset($_POST['content'])) ? $_POST['content'] : null;

Otherwise, use strict comparison to null.

if ($content === null) { }

(Really, I’m just pushing my opinion on your with the strict comparison. I just think it looks better than is_null, and it’s probably an extremely small bit faster.)