Javascript不支持尾递归，让我很蛋疼。。。。

Question

function factorial(n){    alert(fact_iter(1,1,n));}function fact_iter(product, counter, max_count){    if(counter > max_count)    {        return product;            }    else    {        fact_iter(counter*product , counter+1, max_count);            }}factorial(2);</script>   这段代码执行结果是undefined

Answer 1

function factorial(n){
    alert(fact_iter(1,1,n));
}

function fact_iter(product, counter, max_count){
    if(counter > max_count)
    {
        return product;
        
    }
    else
    {
        return fact_iter(counter*product , counter+1, max_count);
        
    }
}

factorial(2);