如何在唯一迭代中从循环中提取值？

Question

所以在 java 这本书的介绍中，我的任务是：

Suppose that the tuition for a university is ,000 this year and increases 5% every year. In one year, the tuition will be ,500. Write a program that computes the tuition in ten years and the total cost of four years' worth of tuition after the tenth year.

我可以很容易地计算出第 10 年的学费，但让我感到困惑的是如何将第 11、12、13 和 14 年的唯一学费值相加。如果我是对的，它应该加起来为 73717.764259 .我的代码给我的是 158394.52795515177。随着代码的发展，可能只是我在以错误的方式思考这个问题并且我的代码正确地进行了添加，但我认为我在这里更正确。这是我现在使用的代码：

    double initialTuition = 10000;
    final double theRate = 0.05;

    for (int i = 1; i < 15; i++) {
        initialTuition = ((theRate * initialTuition) + initialTuition);
        System.out.println("Year " + i + " tuition is: " + initialTuition);
        while (i == 10){
            System.out.println("Year " + i + " tuition is: " + initialTuition);
            double startOfFourYearTuition = initialTuition;
            System.out.println(startOfFourYearTuition);
            break;
        }

        while ((i > 10) && (i < 15)) {
            System.out.println("Year " + i + " tuition is: " + initialTuition);
            initialTuition += initialTuition;
            break;
        }

    }

最后一个 while 循环是我尝试添加 4 年。

重申一下这个问题，我如何在第 11 到 14 次迭代中提取 initialTuition 的唯一值并添加它们？

Answer 1

你也有很多无用的代码，while 循环内部的 for 循环等等。试试这个大小：

public static void main(String[] args) 
{
    double initialTuition = 10000;
    double summarizedTuition = 0;

    final double theRate = 0.05;

    for (int i = 1; i < 15; i++) {
        initialTuition = ((theRate * initialTuition) + initialTuition);
        System.out.println("Year " + i + " tuition is: " + initialTuition);

        if ((i > 10) && (i < 15)) 
        {
            summarizedTuition += initialTuition;
        }
    }

    System.out.println("Summarized tuition for years 11 - 14: " + summarizedTuition);
}

输出为：

Year 1 tuition is: 10500.0
Year 2 tuition is: 11025.0
Year 3 tuition is: 11576.25
Year 4 tuition is: 12155.0625
Year 5 tuition is: 12762.815625
Year 6 tuition is: 13400.95640625
Year 7 tuition is: 14071.0042265625
Year 8 tuition is: 14774.554437890625
Year 9 tuition is: 15513.282159785156
Year 10 tuition is: 16288.946267774414
Year 11 tuition is: 17103.393581163135
Year 12 tuition is: 17958.56326022129
Year 13 tuition is: 18856.491423232354
Year 14 tuition is: 19799.31599439397
Summarized tuition for years 11 - 14: 73717.76425901074

Answer 2

        double theRate = 1.05; // rate of increase +5%
        double tuitionCost = 10000; // base cost
        double fourYearCost = 0; // four year cost (years 10-13)
        for (int i = 0; i <= 13; i++) {
            System.out.println("Cost of year: " + i + " is $" + tuitionCost); // print out this years cost
            if(i >= 10){ //if its year 10, 11, 12, 13
                fourYearCost += tuitionCost; // add this years tuition cost
            }
            tuitionCost *= theRate; // increment the tuition (mutiply it by 1.05, or 5% increase)
        }

        System.out.println("Cost of tuition for years 10, 11, 12, 13: $" + fourYearCost); // print the cost for the remaining years

如何在唯一迭代中从循环中提取值？

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