Local and Global Variables

Local and Global Variables

Local and Global Variables :

1.      A variable which is specified inside a function is called an local variable and a variable which is specify outside the function is called as global variable.

2.      A local variable is accessable only with in the function where it is declared.

3.      Where as a global variable can be accessed from any where in the program.

4.      The lifetime of local variable is only within the function.

$GLOBALS : is a builtin multidimentional global array of php. That stores get data, post data,cookies,uploader files, error messages happening in a program execution and also excludes the global variables of the application.

The variables present inside $GLOBALS array is known as global variables.

Global : is a keyword of php used for declaring a global variable . a variable declared by using the keyword globsl cannot be intialized.

     <?php

$x=10;

function myfun()

{

    $y=20;

    $GLOBALS['y']=20;

    global $z;

    $z = 30;

      

}

?>

<h1>

<?php

echo $x."--".$y."<br>";

myfun();

print_r($GLOBALS);

echo "<br><br>";

echo $x."--".$y."--".$z;

?>

</h1>

OutPut:

10--

Array ( [GLOBALS] => Array *RECURSION* [_POST] => Array ( ) [_GET] => Array ( ) [_COOKIE] => Array ( ) [_FILES] => Array ( ) [x] => 10 [y] => 20 [z] => 30 )

10--20--30