我需要编写一个从数字中减去每月数字的函数

Question

我正在尝试计算每个月信用卡的新余额，我需要从余额中减去每月付款以返回新余额，但不知道如何让它不断减去，直到卡余额为零，请帮忙！

提前谢谢你

var monthly = calculateMinimumPayment(1500);
var bal = 1500;
var i = 0;
while (bal > i) {
bal - monthly;
}
console.log(bal);
function calculateMinimumPayment(a) {
var payment = ((a * .18) / 12) + (a * .02);
return payment;
}

Answer 1

试试这个，我不确定这是否是你想要的，如果不是，请在下面评论：

var monthly = calculateMinimumPayment(1500);
var bal = 1500;
var i = 0;
while (bal > i) {
bal -= monthly;
}  
console.log(bal);
function calculateMinimumPayment(a) {
var payment = ((a * .18) / 12) + (a * .02);
return payment;
}

Answer 2

您需要通过执行bal = bal - monthly来更新while循环中bal的值。

如果您希望bal的值为非负值，则需要在while循环条件中再添加一个条件，只需执行(bal - monthly) >= 0即可。

var monthly = calculateMinimumPayment(1500);
var bal = 1500;
var i = 0;
while (bal - monthly >= 0) {
bal = bal - monthly;
}
console.log(bal);
function calculateMinimumPayment(a) {
var payment = ((a * .18) / 12) + (a * .02);
return payment;
}