Question

我是编程新手，我很感激这个问题的帮助：一个计算经济援助金额的计划。如果家庭年收入在3万至4万美元之间且家庭至少有3个孩子，则每名儿童的收入为1000美元。如果家庭年收入在2万至3万美元之间且家庭至少有3个孩子，则每名儿童的收入为1500美元。如果家庭年收入低于20000美元，则每名儿童的收入为2000美元。我必须实现一个方法并使用-1作为sentinel值。这是我目前的计划

public static void main(String[] args) {
    // **METHOD** //
    Scanner in = new Scanner(System.in);

    System.out.println("What is the annual household income?");
    double income = in.nextDouble();

    System.out.println("How many children are in the household?");
    int children = in.nextInt();

    System.out.println("The financial assistance for this household is: "
                        + assistance(income, children));
}
    //**TEST PROGRAM**//
public static double assistance(double income, int children)
{
    if(income >= 30000 && income < 40000 && children >= 3)
    {
        assistance = children * 1000; //says that it cannot find the symbol
    }

    else if(income >= 20000 && income < 30000 && children >= 2)
    {
        assistance = children * 1500;
    }
else if(income < 20000)
    {
        assistance = children * 2000;
    }
else
    {
        assistance = 0.0;
    }

    return assistance;
}
}

Answer 1

您可能正在考虑另一种语言，例如Basic，您声明一个函数并使用函数的名称返回函数的值。

Java只是让你返回值。

其他人已经宣布assistance。请考虑使用其他名称ans的变量。最后，您将返回ans。

public static double assistance(double income, int children)
{
    double ans = 0.0;
    if(income >= 30000 && income < 40000 && children >= 3)
    {
        ans = children * 1000; //says that it cannot find the symbol
    }

    else if(income >= 20000 && income < 30000 && children >= 2)
    {
        ans = children * 1500;
    }
else if(income < 20000)
    {
        ans = children * 2000;
    }

    return ans;
}
}

Answer 2

您需要在assistance

的开头声明function public static double assistance

public static double assistance(double income, int children)
{
   double assistance = 0.0;

   "Rest of your code here"
}

Answer 3

首先，我假设您拥有在类中列出的代码，因为在Java中，所有内容都是类。截至目前，您尚未定义可变辅助。因此，我建议您验证输入，以便处理用户未输入数值的实例。另一个想法是将援助作为一个对象，因为它不必是静态的。然后，您可以使用该对象来调用辅助方法。像这样：

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
    // **METHOD** //
    Scanner in = new Scanner(System.in);

    System.out.println("What is the annual household income?");
    double income = in.nextDouble();

    System.out.println("How many children are in the household?");
    int children = in.nextInt();

    System.out.println("The financial assistance for this household is: "
            + new Assistance.getAssistance(income,children));
}

}

public class Assistance {
    public double getAssistance(double income, int children) {

    /* Declare assistance here */
    double assistance;
    if (income >= 30000 && income < 40000 && children >= 3) {
        assistance = children * 1000; // says that it cannot find the symbol
    }

    else if (income >= 20000 && income < 30000 && children >= 2) {
        assistance = children * 1500;
    } else if (income < 20000) {
        assistance = children * 2000;
    } else {
        assistance = 0.0;
    }

    return assistance;
}
}

经济援助计算器

3 个答案: