How to Check for a Specific Type of Object in PHP

Question

I have a method which accepts a PDO object as an argument, to allow the user to use an existing connection rather then the method to open a new one, and save resources:

public static function databaseConnect($pdo = null) {

I am aware of is_object() to check if the argument is an object, but I want to check if $pdo is a PDO object, and not just an object.

Because the user can easily enter (by mistake?) a different kind of object, a mysqli or such, and the entire script will break apart.

How can I check a variable for a specific type of object?

Answer 1

Hello @kartik,

Use:

 bool is_a ( object $object , string $class_name )

This will work for child classes too.

Or you could use type hinting:

public static function databaseConnect(PDO $pdo = null) {...

Hope it helps!!