java - 循环验证和输出问题

Question

所以我一切正常，除了输入所需的输入后，我会得到如下输入:

1   5.0
2   6.0
3   7.0
4   8.0

我不知道我做错了什么，因为根据我输入的增长率(50)，它似乎没有以正确的增量增加。也无法让有机体数量根据第二天增加。有什么建议吗？

//Purpose of program to predict population of organisms

import java.util.Scanner;

public class Population {
    public static void main(String[] args) {
        double growthRate = -1;
        int population = 0;
        int days = -1;
        double popResult = 0;

        Scanner keyboard = new Scanner(System.in);

        System.out.println("\nEnter the starting number of organisms:");
        population = keyboard.nextInt();

        while (population < 2) {
            System.out.println("\nError!! Please re-enter number of organisms.");
            population = keyboard.nextInt();
        }

        System.out.println("\nEnter rate of growth as percentage:");
        growthRate = keyboard.nextInt() / 100;

        while (growthRate < 0) {
            System.out.println("\nError!! Growth rate must be a positive number. Please re-enter.");
            growthRate = keyboard.nextInt();
        }

        System.out.println("\nEnter number of days organisms will grow:");
        days = keyboard.nextInt();

        while (days < 0) {
            System.out.println("\nError!! Number of days cannot be less than 1. Please re-enter.");
            days = keyboard.nextInt();
        }

        System.out.println("Days" + "\t" + "Organisms");
        System.out.println("------------------");

        popResult = population;
        growthRate = growthRate / 100;

        for (int numberOfDays = 1; numberOfDays < days; numberOfDays++) {
            System.out.println(numberOfDays + "\t" + popResult);
            popResult = (popResult * growthRate) + popResult;

        }
    }
}

Answer 1

您正在行中以整数格式输入 GrowthRate

growthRate=keyboard.nextInt()/100;

如果它小于 0，那么您将输入不除以 100

growthRate=keyboard.nextInt();

最后你再次将 GrowthRate 除以生长率=生长率/100；

因此，您必须仅在 while 循环之外获取输入GrowthRate=keyboard.nextInt();

修改后的代码

import java.util.Scanner;

public class Population
{
    public static void main(String[] args)
    {
        double growthRate=-1;
        int population=0;
        int days=-1;
        double popResult=0;

        Scanner keyboard=new Scanner(System.in);

        System.out.println("\nEnter the starting number of organisms:");
        population=keyboard.nextInt();

        while(population<2)
        {
            System.out.println("\nError!! Please re-enter number of organisms.");
            population=keyboard.nextInt();
        }

        System.out.println("\nEnter rate of growth as percentage:");
        growthRate=keyboard.nextInt();

        while(growthRate<0)
        {
            System.out.println("\nError!! Growth rate must be a positive number. Please re-enter.");
            growthRate=keyboard.nextInt();
        }

        System.out.println("\nEnter number of days organisms will grow:");
        days=keyboard.nextInt();

        while(days<0)
        {
            System.out.println("\nError!! Number of days cannot be less than 1. Please re-enter.");
            days=keyboard.nextInt();
        }

        System.out.println("Days" + "\t" +  "Organisms");
        System.out.println("------------------");

        popResult=population;
        growthRate=growthRate/100;

        for(int numberOfDays=1; numberOfDays<days; numberOfDays++)
        {
            System.out.println(numberOfDays + "\t" + popResult);
            popResult=(popResult * growthRate) + popResult;

        }}}