函數(shù)

/**
 計(jì)算本息和

 @param principal 本金
 @param time 時(shí)間(天)
 @param sevenyearInterestRate 七日年利率
 */
static void CalculateRevenue(double principal,int time,double sevenyearInterestRate){
    double principalAndInterest = principal;
    double interest = sevenyearInterestRate/365;// 日利率
    for (int i = 0; i<time; i++) {
        principalAndInterest += principalAndInterest*interest;
    }
    NSLog(@"本金%f \n 經(jīng)過(guò)%d天\n 本息和%f\n 盈利%f",principal,time,principalAndInterest,(principalAndInterest-principal));
}

使用

// 計(jì)算余額寶本息和
    double principal = 50000.00f;//本金
    int time = 485;//時(shí)間
    double sevenyearInterestRate = 0.03886f;// 七日年利率
    CalculateRevenue(principal,time,sevenyearInterestRate);

log如下

 本金50000.000000 
 經(jīng)過(guò)485天
 本息和52649.468744
 盈利2649.468744

復(fù)雜一點(diǎn)，引入一些定制化的需求(比如每月會(huì)取款一定金額)