Using Static Variables in PHP: A Comprehensive Guide

In contrast to the variables declared as function parameters, which are destroyed on the function's exit, a static variable will not lose its value when the function exits and will still hold that value should the function be called again.

You can declare a variable to be static simply by placing the keyword STATIC in front of the variable name.

Syntax:

<?php
   function trackerFunction() {
      STATIC $count = 10;
      $count++;
      print $count;
      print "<br />";
   }
   
   trackerFunction();
   trackerFunction();
   trackerFunction();
?>

Output:

This will produce the following result

11
12
13

we will discuss more about static keyword later