Static Variables in PHP

In addition to local and global variables, there is another type of variable in PHP - static variables .

If the body of the user function is declared static variable , the compiler will not delete it after the completion of this function.

Static variable declaration:

<?php
function funct(){
static $int = 0; // верно
static $int = 1+2; // неверно (поскольку это выражение)
static $int = sqrt(121); // неверно (поскольку это тоже выражение)

$int++;
echo $int;
}
?>

An example of a user function containing static variables:

<? php
    function funct ()
    {
       static   $ a ;
       $ a ++;
echo "$a" ;
    }
    for   ($ i = 0 ;   $ i ++< 10 ;) funct ();
?>

This script displays the line:

1 2 3 4 5 6 7 8 9 10

If we remove the static statement, the line will be displayed:

1 1 1 1 1 1 1 1 1 1

This is due to the fact that the $ a variable will be deleted at the end of the function and will be reset every time it is called. The variable $ a is incremented immediately after zeroing, and only then displayed.

See also:

Local Variables in PHP

Global variables in php