PHP Functions

Similar to other programming languages, PHP provides a way for programmers to define functions, which can then be called elsewhere in the program. The syntax for a function is:

function "function_name" (arg1, arg2...)
{
  [code to execute]
  return [final_result];
}

where [final_result] is typically the variable holding the final value to be returned from the function.

Let's take a look at an example:

function double_this_number($input_number) {   return $input_number*2; }

Elsewhere in the PHP code, we have

$x = 10; $y = double_this_number($x); print $y;

The output will be

20