Often you'd want to execute a statement if a certain condition is met, and a different statement if the condition is not met. This is what else is for. else extends an if statement to execute a statement in case the expression in the if statement evaluates to FALSE. For example, the following code would display a is bigger than b if $a is bigger than $b, and a is NOT bigger than b otherwise:
<?php
if ($a > $b) {
echo "a is bigger than b";
} else {
echo "a is NOT bigger than b";
}
?>