#! code

When creating functions in PHP it is possible to provide default parameters so that when a parameter is not passed to the function it is still available within the function with a pre-defined value. These default values can also be called optional parameters because they don't need to be passed to the function. I have seen this sort of code being used incorrectly quite often recently so I thought I would go over it in a post.

Creating a default parameter in a function is very simple and is quite like normal variable assignment. The following function has a single parameter that is set to 1 if it is not passed when calling the function.

function testFunction($a = 1)
{
    return $a;
}