php global variable in function code example

Example 1: php global variable function

<?php
  $myVariable = "a";
  function changeVar($newVar) {
    global $myVariable
    $myVariable = "b";
  }
  echo $myVariable; // Should echo b
?>

Example 2: how make a variable global php

$a = 1;
$b = 2;
function Sum(){
    global $a, $b; // allows access to vars outside of function
    $b = $a + $b;
} 

Sum();
echo $b; // output is 3

Example 3: php globals

$GLOBALS["foo"]