Скачать или смотреть Learn PHP Tutorial 14 Function with Default Arguments

This video is made for learning about Function with Default Arguments in PHP.

PHP functions are similar to other programming languages. A function is a piece of code which takes one more input in the form of parameter and does some processing and returns a value.

Function arguments

Information may be passed to functions via the argument list, which is a comma-delimited list of expressions. The arguments are evaluated from left to right.

PHP supports passing arguments by value (the default), passing by reference, and default argument values. Variable-length argument lists are also supported.

Default parameters
When designing your functions, it is often helpful to be able to assign default values for parameters that aren't passed - PHP does this for most of its functions, and it saves you having to pass in parameters most of the time if they are usually the same.