Math calculation
<? $somevar = 5 + 5; // 10 $somevar = 5 - 5; // 0 $somevar = 5 + 5 - (5 + 5); // 0 $somevar = 5 * 5; // 25 $somevar = 10 * 5 - 5; // 45 $somevar = $somevar . "appended to end"; $somevar = false; $somevar = !$somevar; // $somevar is now set to true $somevar = 5; $somevar++; // $somevar is now 6 $somevar--; // $somevar is now 5 again ++$somevar; // $somevar is 6 ?>