<?php
echo "\$a = $a\n";
echo "\$b = $b\n";
if ($a > $b) {
  echo "a is bigger than b";
  $b = $a;
}

$a = 7;
echo "\$a = $a\n";
$b = 5;
echo "\$b = $b\n";
if ($a > $b) {
  echo "a is bigger than b";
  $b = $a;
}
echo "the biggest between \$a and \$b is $b";
?>

<?php
unset($a);
unset($b);
if ($a > $b) {
  echo "a is greater than b";
} else {
  echo "\$a == $a is NOT greater than \$b == $b\n";
}
?>

<?php
if ($a > $b) {
    echo "a is bigger than b";
} elseif ($a == $b) {
    echo "a is equal to b";
} else {
    echo "a is smaller than b";
}
?>

// Giampaolo suggestion:
<?php
if ($a > $b) {
    echo "a is bigger than b";
} elseif ($a = $b) {
    echo "a is equal to b";
} else {
    echo "a is smaller than b";
}
?>