Java程序，以交互方式顯示幾何圖形中的形狀數量

Question

我有這個Java程序，應該顯示三角形，梯形和六邊形的幾何形狀的邊數。 我設法創建了代碼，以便當我運行java Shape時，它可以一次顯示所有Shapes和所有邊，但是我想使其具有交互性，以便可以提示用戶輸入她想要的形狀，並且返回它的邊數多少，Java中的哪個功能可以最好地做到這一點？

public abstract class Shape {

    public abstract void numberOfSides();

    public static void main(String[] args)
    {
        System.out.println("The Geometrical characteristics of the figures are as follows");

        Trapezoid t=new Trapezoid();
        Triangle tg=new Triangle();
        Hexagon h=new Hexagon();
        t.numberOfSides();
        tg.numberOfSides();
        h.numberOfSides();
    }
}
class Trapezoid extends Shape {
    public void numberOfSides()
    {
        System.out.println("Trapezoid~It is geometrical figure with an attribute of 4 sides (Of which two are parallel and with no angles)");
    }
}
class Triangle extends Shape {
    public void numberOfSides()
    {
        System.out.println("Triangle~It is geometrical figure with an attribute of 3 sides");   
    }
}   
class Hexagon extends Shape {
    public void numberOfSides()
    {   
        System.out.println("Hexagon-It is geometrical figure with an attribute of 6 sides");
    }
}

這是我嘗試實施以上方法后的新方法，它說存在錯誤，已經過時了。

import java.io.*;
 public abstract class Shape {

    public abstract void numberOfSides();

    public static void main(String[] args) 
    {  
        System.out.println("Enter the name of the Shape");
        BufferedReader br = new BufferedReader (new InputStreamReader(System.in));
        try {
        String shapeName = br.readLine();

        if (br.equals ("Trapezoid"))
                {Trapezoid t = new Trapezoid();
                t.numberOfSides();
                }
        else if (br.equals ("Triangle"))    
                {Triangle tg = new Triangle();
                tg.numberOfSides();
                }
        else if (br.equals ("Hexagon")) 
                {Hexagon h = new Hexagon();
                h.numberOfSides();
                }
                }    
}
class Trapezoid extends Shape {
    public void numberOfSides()
{
        System.out.println("Trapezoid~It is geometrical figure with an attribute of 4 sides (Of which two are parallel and with no angles)");
}
}
class Triangle extends Shape {
    public void numberOfSides()
{
        System.out.println("Triangle~It is geometrical figure with an attribute of 3 sides");   
}
}   
class Hexagon extends Shape {
    public void numberOfSides()
{   
        System.out.println("Hexagon-It is geometrical figure with an attribute of 6 sides");
}
}

Answer 1

要從用戶讀取輸入，您將要使用緩沖讀取器。 然后，您需要根據用戶輸入有條件地調用您的方法。

例如

System.out.println("Enter the name of the shape");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String shapeName = br.readLine();

if(br.equals("Trapezoid") {
   Trapezoid t = new Trapezoid();
   t.numberOfSides();
}
//...

編寫完該代碼后，您可以實現一個菜單，供用戶選擇所需的形狀。 該代碼看起來像這樣。

System.out.println("Select one of the following shapes. \n 1) Trapezoid \n 2) Triangle \n 3) Hexagon");
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String shapeName = br.readLine();

if(br.equals("Trapezoid" || br.equals("1") {
   Trapezoid t = new Trapezoid();
   t.numberOfSides();
}
// ...