Variables

  • Variable is Special type of container which can hold the value .

  • A variable consists of a name that you can choose, preceded by a dollar ($) sign.

  • The variable name can include letters, numbers, and the underscore character (_).

  • Variable names cannot include spaces or characters that are not alphanumeric, and they should begin with a letter or an underscore.

    • The following code defines some legal variables:-
    $var;
    $_635263;
    $abbABC;
    $num = 8;
    print $num;


PHP Variable Scopes :


Local Scope :
A variable which is declared within a PHP function is local and can only be accessed within that function.
Example :
<?php
function myFun() 
{
	echo $var; // local scope 
} 
myFun(); 
?>


Global Scope :
A variable which is defined outside of any function, has a global scope.

Example : 
<?php 
$var=10; //global scope
	function myFun() 
{
	echo $var; // local scope 
} 
myFun(); 
?>


Static Scope :
Static variable never lose its value whenever function exists. Saving State Between Function Calls with static variable.
Example :
<?php
function myFun()
{
	static $x=0;
	echo $x;
	$x++;
}
myFun();
myFun();
myFun();
myFun();
?>


Parameter Scope :-
A parameter is a local variable whose value is passed to the function .
Example :
<?php
function myFun($y)
{
	echo $y;
}
myFun(5);
?>