A key benefit of using functions is that they are reusable; if you have a task that needs to be performed a number of times, a function is an ideal solution. They can be either defined by you or by PHP (PHP has a rich collection of built-in functions). This article will focus on programmer-defined functions but will touch briefly on PHP’s functions to complete the picture.

<?php 

$variable1 = 0;

function function1(){
	//$variable1 = 10;
	global $variable1;
	return $variable1;
}


function function2(){
	//$variable1 = 10;
	global $variable1;
	return $variable1;
}


function add2Numbers($num1, $num2) {
    $result = $num1 + $num2;
    return $result;
}


echo function1();
echo function2();
echo add2Numbers(10,20);


/*PHP The static Keyword*/


function myTest() {
  static $x = 0;
  echo $x;
  $x++;
}

myTest();
myTest();
myTest();

 ?>