检查并更正我的代码。 （我是初学者）

Question

有人可以帮我纠正我的代码吗？它被创建用于计算住房贷款（UMI），编码是正确的，但它没有完全显示输出。在“输入贷款期限”后，它显示一个框。还有另一种方法来设置class Variables中的变量吗？

package assignment.pkg2;
import java.util.Scanner;//for Scanner
import java.text.DecimalFormat;//for using decimal format

class Variables{ //set the variables
    private double p, r, n;

    public void setVarP (double amount){
        this.p = amount;
    }
    public void setVarR (double rate){
        this.r = rate;
    }
    public void setVarN (int duration){
        this.n = duration;
    }
    public double getVarP(){
        return p;
    }
    public double getVarR(){
        return r;
    }
    public double getVarN(){
        return n;
    }
}

class EMIcalc{ //the calculating part
    private double monthlyPay, pow;
   Variables var = new Variables();
    Scanner scanner = new Scanner(System.in);

    public void getPay(){
        pow = Math.pow (1+(var.getVarR()/12), - var.getVarN());
        monthlyPay = var.getVarP() * ( (var.getVarR()/12) / (1 - pow) );

        DecimalFormat Dformat = new DecimalFormat("##.##");
        System.out.println(Dformat.format(monthlyPay));
    }

}

public class Assignment2 {

        public static void main(String[] args) {
            Variables var1 = new Variables();
            EMIcalc calc = new EMIcalc();
            Scanner scanner = new Scanner(System.in);

            System.out.println("Enter your loan amount");
            var1.setVarP(scanner.nextDouble());

            System.out.println("Enter interest rate");
            var1.setVarR(scanner.nextDouble());

            System.out.println("Enter loan duration");
            var1.setVarN(scanner.nextInt());

            calc.getPay();
        }
}

Answer 1

您正在将值设置为var1，但calc会查看其内部var字段，该字段是另一个对象。您只需将var1.set...替换为calc.var.set...。

或者您可以将Variables和EMIcalc类合并为一个。

Answer 2

你在找这个吗？

import java.text.DecimalFormat;
import java.util.Scanner;

class Variables { //set the variables
    private double p, r, n;

    public double getVarP() {
        return p;
    }
    public void setVarP(double amount) {
        this.p = amount;
    }
    public double getVarR() {
        return r;
    }
    public void setVarR(double rate) {
        this.r = rate;
    }
    public double getVarN() {
        return n;
    }
    public void setVarN(int duration) {
        this.n = duration;
    }
}

class EMIcalc { //the calculating part
    Variables var = new Variables();
    Scanner scanner = new Scanner(System.in);
    private double monthlyPay, pow;

    public void getPay() {
        pow = Math.pow(1 + (var.getVarR() / 12), -var.getVarN());
        monthlyPay = var.getVarP() * ((var.getVarR() / 12) / (1 - pow));
        DecimalFormat Dformat = new DecimalFormat("##.##");
        System.out.println(Dformat.format(monthlyPay));
    }
}

public class Assignment2 {

    public static void main(String[] args) {
        EMIcalc calc = new EMIcalc();
        Scanner scanner = new Scanner(System.in);

        System.out.println("Enter your loan amount");
        calc.var.setVarP(scanner.nextDouble());
        System.out.println("Enter interest rate");
        calc.var.setVarR(scanner.nextDouble());
        System.out.println("Enter loan duration");
        calc.var.setVarN(scanner.nextInt());

        calc.getPay();
    }
}

PS：自己尝试分配。