斐波那契数列的实现(递归与非递归)

   //非递归实现
    function foo(number) {
        if(number !== 'number' && number%1 !== 0){
            console.error('您输入的数字不符合规范');
        }

        let fv = 1 , sv = 1 , target ,  flag = 2;

        if(number <= 2 ){
            return 1;
        }

        while(true){
            target = fv + sv;
            fv = sc;
            sv = target;
            flag++;
            if(flag === number){
                break;
            }
        }

        return target;
    }

    //递归实现
    function foo1(number){
        if(number <= 2){
            return 1;
        }else{
            return foo1(number - 1 ) + foo1(number - 2);
        }
    }