Creating Optional Parameters in PHP

In PHP, the function syntax for optional parameters is denoted by square brackets around the parameter set. For instance, the date() function expects the following format:

string date ( string $format [, int $timestamp = time() ] )

Here, $timestamp is optional and defaults to the value returned by time().

Defining Optional Parameters in Custom Functions

To create optional parameters in your own custom functions, simply utilize the equals sign (=) within the parameter definition. For example:

function doSomething($var1, $var2, $var3 = 'somevalue'){
    // Rest of function here...
}

In this example, $var3 is optional and will default to 'somevalue' if not specified.