When to use a static variable in a function in PHP?

The following code shows an example of using static variable in a function in PHP.

When we use static variable in a function in PHP, it retains its value across function calls. In other words, the value updated by the function for a static variable is retained even after the function returns. Subsequent calls to the same function use the updated values.

The Example Code to Demonstrate Static Variable in a Function in PHP

In the following code, the variable x is static in the function myfunction(). When the first function call updates the value of x to 10, the variable x retains its value. In all subsequent function calls, the update value is used.

<?php
   function myfunction()
   {
      static $x=0;
      $y=0;
    
      $x+=10;
      $y+=10;
      echo 'Value of static variable x = ',$x,'<br>';
      echo 'Value of non-static variable y = ',$y,'<br>';
    }
    echo 'First Function Call...<br>';
    myfunction();
    echo 'Second Function Call...<br>';
    myfunction();
    echo 'Third Function Call...<br>';
    myfunction();
?>

Output

**Example of using static variable in a function in PHP**

Apart from using static in a function, we can have static properties and methods in a class also. An example of using static keyword with properties and methods of a class is given here.

The Example Code to Demonstrate Static Variable in a Function in PHP

Further Reading