php如何解决青蛙跳台阶的问题（代码）

JumpFloor(target)
    if target==1 || target==2 return target
    jumpSum=0
    jump1=1
    jump2=2
    for i=3;i<target;i++
        jumpSum=jump1+jump2
        jump1=jump2
        jump2=jumpSum
    return jumpSum

function jumpFloor($number)
{
        if($number==1 || $number==2){
                return $number;
        }   
        $jumpSum=0;
        $jump1=1;
        $jump2=2;
        for($i=3;$i<=$number;$i++){
                $jumpSum=$jump1+$jump2;
                $jump1=$jump2;
                $jump2=$jumpSum;
        }   
        return $jumpSum;
}
$res=jumpFloor(10);
var_dump($res);