小程序中贷款计算器中先息后本还款方式，显示明细代码怎么实现，看一下公式怎么写

Question

/**
 * 每月还息到期还本
 * @param {*贷款总额} total
 * @param {*还款月数} months
 * @param {*月利率} monthRate
 */
const equalPrincipall = (total, months, monthRate) => {
    // 每月月供额 = 每月应还利息   
    // 每月应还本金 = 0     
    // 每月应还利息 = 贷款总额 × 月利率  
    let interest = total * monthRate;   //本期利息
    //let principal =interest/monthRate;   //本期本金
      let monthlyPayment=interest;
      return monthlyPayment;
}
let tempTotalPaid = 0;
/**
 *  //本期本金
 * @param {*待还本金} surplus
 * @param {*没有偿还本息} monthlyPayment
 * @param {*月利率} monthRate
 */
const equalPrincipalll = (surplus, monthlyPayment, monthRate) => {
    let interest = surplus * monthRate;   //本期利息
    let principal =0;     //本期本金
    surplus = surplus ;             //剩余本金
    return {
        monthlyPayment: monthlyPayment,
        principal: principal,
        interest: interest,
        surplus: surplus
    }
}

Answer 1

题主，这个文章中有JS版本的计算方法，可以参考下。红色的字是关键的计算公式。

https://blog.csdn.net/qm19900331/article/details/48290257