編寫一個 java 程序，在用戶輸入尺寸后根據用戶的選擇打印圓形、矩形或三角形

Question

編寫一個 java 程序，提示用戶選擇要顯示在屏幕上的形狀。 用戶選擇一個三角形、圓形或矩形，並提示用戶提供用於計算的尺寸，然后繼續並將形狀打印在屏幕上。

我試過了但不幸的是失敗了。 這是代碼。

import java.*;
import java.util.Scanner;

public class shape {
    public static void main(String[] args) {
        int P;
        int x, y;
        int r;
        r = 0;
        double shape;
        int c;
        int height;
        int width;

        Scanner reader = new Scanner(System.in);
        System.out.print("Choose a shape : ");
        shape = reader.nextInt();
        double circle;
        circle = 0;
        double rectangle;
        rectangle = 0;
        double triangle;
        triangle = 0;

        if (shape == circle) { 
            P = 2 * r;

            for (int i = 0; i <= P; i++) {
                for (int j = 0; j <= P; j++) {
                    x = r - i;
                    y = r - j;

                    c = x*x + y*y ;
 
                    if (c <= r * r + 1) {
                        System.out.print("* ");
                    }
                    else {
                        System.out.print("  ");
                    }
                }

                System.out.println();
            }
       }
       else if(shape == rectangle) {
           Scanner scan = new Scanner(System.in); 
           System.out.print("Enter the number of widths: ");
           width = scan.nextInt();

           // get input from the user for width
           System.out.print("Enter the number of widths: ");
           height = scan.nextInt();

           // get input from the user for column
           for (int i = 1; i <= width; i++) {
               for (int j = 1; j <= height; j++) {
                   System.out.print("*");
               }
               System.out.print("\n");
           }

           if (shape == triangle) {
               Scanner sc = new Scanner(System.in);
               System.out.println("Enter the number of rows to be printed");
               int rows = sc.nextInt();

               for (int i = 1; i <= rows; i++) {
                   for (int j = rows; j >= i; j--) {
                       System.out.print(" ");
                   }
           
                   for (int j = 1; j <= i; j++) {
                       System.out.print("* ");
                   }
            
                    System.out.println();
                }
            }
        }
    }
}

Answer 1

我想到了。

import java.util.Scanner; 
public class shapes2 {
    public static void main(String[] args){

        Scanner in = new Scanner(System.in);
        
        System.out.println("Enter c to calculate area of circle");
        System.out.println("Enter s to calculate area of square");
        System.out.println("Enter r to calculate area of rectangle");
        System.out.print("Enter your choice: ");
        char choice = in.next().charAt(0);
        
        switch(choice) {
            case 'c':
            double distance;
            int rad;
            Scanner sc = new Scanner(System.in);
            System.out.print("Enter any value for radius: ");
            rad = sc.nextInt();
            System.out.println("Circle Pattern:\n");
            for (int row = 0; row <= 2 * rad; row++) {
                for (int col = 0; col <= 2 * rad; col++) {
                    distance = Math.sqrt((row - rad) * (row - rad) + (col - rad) * (col - rad));

                    if (distance > rad - 0.5 && distance < rad + 0.5)
                        System.out.print("*");
                    else
                        System.out.print(" ");
                }
                System.out.println();
            }
                break;
                
            case 's':
            int side, i, j;
            Scanner scs = new Scanner(System.in);
            
            System.out.print(" Please Enter any Side of a Square : ");
            side = scs.nextInt();   
                
            for(i = 1; i <= side; i++)
            {
                for(j = 1; j <= side; j++)
                {
                    System.out.print("*"); 
                }
                System.out.print("\n"); 
            }   
                break;
                
            case 'r':
            int rows, columns, x, y;
            sc = new Scanner(System.in);
            
            System.out.print(" Please Enter Number of Rows : ");
            rows = sc.nextInt();    
            
            System.out.print(" Please Enter Number of Columns : ");
            columns = sc.nextInt();     
                
            for(x = 1; x <= rows; x++)
            {
                for(y = 1; y <= columns; y++)
                {
                    System.out.print("* "); 
                }
                System.out.print("\n"); 
            }
                break;
                
            default:
                System.out.println("Wrong choice!");
        }
    }
}