练习1:求一个数字的阶乘
function getJieCheng(num) { var result = 1; for (var i = 1; i <= num; i++) { result *= i; } return result; } console.log(getJieCheng(6)); //1*2*3*4*5*6
练习2:求一个数字的阶乘和
ps:
5的阶乘和:即5的阶乘+4的阶乘+3的阶乘+2的阶乘+1的阶乘
function getJieChengSum(num) { var sum = 0; //和 for (var i = 1; i <= num; i++) { sum += getJieCheng(i); } return sum; } console.log(getJieChengSum(5)); // 1+2+6+24+120 //函数内部可以调用其它函数
*函数function getJieCheng(num)被调用了: