降低每月付款的算法

问题描述

我试图获得一个可以每月自动降低价格的系统，所以在12月，您支付价格的1/12，在2月，您支付价格的11/12，依此类推。

但是我似乎无法解决问题，所以我在这里寻求帮助：）

function calcTotalPrice(){
    var month = new Array();
        month[0] = "January";
        month[1] = "February";
        month[2] = "march";
        month[3] = "April";
        month[4] = "May";
        month[5] = "June";
        month[6] = "July";
        month[7] = "August";
        month[8] = "September";
        month[9] = "October";
        month[10] = "November";
        month[11] = "December";

    var d = new Date();
    var n = month[d.getMonth()];
    // document.getElementById("demo").innerHTML = n;
    var yearPrijs = 12.5;
    var membership = new Array();
    if (month[0]){
        membership[0] = yearPrice;
    }
    else{
        for(i = 0;i < month.length; i++){
            yearPrice = yearPrice*0.9167;
            membership[i] = yearPrice;
        }
    }
}

解决方法

好吧@jssse，我想我明白了。

let startDate = new Date();
let startPrice = 12.5;

// Copy the date/price for use in the loop
let newDate = startDate;
let newPrice = startPrice;

let monthly = [];
let totalPrice = 0;

let month = new Array();
  month[0] = "January";
  month[1] = "February";
  month[2] = "March";
  month[3] = "April";
  month[4] = "May";
  month[5] = "June";
  month[6] = "July";
  month[7] = "August";
  month[8] = "September";
  month[9] = "October";
  month[10] = "November";
  month[11] = "December";


// Uncomment either:

// To start from this month,if it is January,or January next year if not
// So,for September 2020,this will be January 2021

//let startMonth = newDate.getMonth();
//if (startMonth != 0) {
//  newDate = new Date(newDate.setMonth(12));
//}

// OR:
// To start from January this year,no matter what month we are in
// so,this will be January 2020

newDate = new Date(newDate.setMonth(0));



for (let i = 0; i < 12; i++) {
  newPrice = Math.round(newPrice * 100)/100;
  monthly.push({"Month": month[newDate.getMonth()],"Cost": newPrice});
  totalPrice += newPrice;
  // create the new date/price for next month
  //newPrice = newPrice - (newPrice * (1 / 12));
  newPrice = newPrice - (startPrice / 12);
  let m = newDate.getMonth() + 1;
  newDate = new Date(newDate.setMonth(m));
}
console.table(monthly);
console.log(totalPrice);

对于这样的事情，通常最简单的方法是在电子表格中构建某些内容-获得所需的结果后，便有了可以转换为javascript代码的公式。在这种情况下，这只是每月将金额减少1/12的一种情况-但仅在处理了第一个月之后（就像在电子表格中一样-您只将公式放在第二行之后）。

通常，在输出数组时，我会使用console.table（arrayname）-但这在片段中似乎不起作用，因此我改用了console.log，因此您可能必须将代码复制到您自己的html文件以查看数组值。

function function function javascript