用java计算形状面积的方法

Question

嗨，我是编程新手，我想用子模块找出圆的面积

我的主电路应该是circleCalc，所有的输入和输出在子模块中分开

请帮我拿一下好吗？还有一些关于返回类型的解释，我不太确定void是做什么的

import java.util.*;
public class shapeCalc
{
    public static void main( String [] args)
    {
     double circleCalc, circle;
     circleCalc();

    }

    public static double intInput(String inputStatement)
    {
        double diameter;
        Scanner sc = new Scanner(System.in);
        System.out.println(inputStatement);
        diameter = sc.nextInt();
        return diameter;
    }

    public static double calcCircleArea(double diameter)
    {
        double radius, area;
        radius = (double)diameter / 2.0;
        area = Math.PI * radius * radius;
        return area;
    }

    public static String extractOutput (double area)
    {
        String output;
        double fraction, mm, m, cm;
        fraction = area - (int)area;
        mm = fraction *100.0;
        m = (int)area / 10000;
        cm = (int)area % 10000;
        System.out.println("area is" + m + cm + mm);
    }

    public static void circleCalc ()
    {
        double diam, area, extractOutput;
        diam = intInput("enter diameter");
        area = calcCircleArea(diam);
        extractOutput(area);
    }
}

Answer 1

返回类型为void的方法不返回任何内容。 查看您的问题，您似乎想要打印/显示区域。 所以我对你现有的代码做了一些修改

public static void main(String[] args) {        
        System.out.println("Area :" + circleCalc());
    }

public static double intInput(String inputStatement) {
no change;}

public static double calcCircleArea(double diameter) {
no change;}

public static String extractOutput(double area) {
        String output;
        double fraction, mm, m, cm;
        fraction = area - (int) area;
        mm = fraction * 100.0;
        m = (int) area / 10000;
        cm = (int) area % 10000;
        output = String.valueOf(m + cm + mm);
        return output;
    }
 public static String circleCalc() {
        double diam, area;
        diam = intInput("enter diameter");
        area = calcCircleArea(diam);
        return extractOutput(area);
    }