PHP水仙花数

打印100-999之间的所有水仙花数

<?php
$num = 100;
while($num <= 999){
    $gw = $num%10;
    $sw = ($num%100-$gw)/10;
    $bw = ($num-$num%100)/100;
    if($sw*$sw*$sw+$bw*$bw*$bw+$gw*$gw*$gw == $num){
        echo $num;
        echo "<br/>";
    }
    $num++;
    }
?>

For（初始条件；结束条件；步长）{

如果条件结束为true，接着循环

}