Java编写四边形

1，正方形

private static void fun1() {
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要打的边长数：");
        int a = sc.nextInt();
        for (int i = 0; i < a; i++) {
    
    	//打印正方形的高
            for (int j = 0; j < a; j++) {
    
    	//打印正方形的长
                System.out.print("*"+"  ");
            }
            System.out.println(" ");
        }
    }

2，平行四边形

 //平行四边形
    private static void fun2() {
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要打的边长数：");
        int a = sc.nextInt();
        for (int i = 1; i <= a; i++) {
    
    
            for (int j = 1; j < i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j <= a; j++) {
    
    
                System.out.print("*"+"  ");
            }
            System.out.println("  ");
        }
    }

3，打印三角形

private static void fun3() {
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要打的边长数：");
        int a = sc.nextInt();
        for (int i = 1; i <= a; i++) {
    
    
            for (int j = 1; j <= a-i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j < i; j++) {
    
    
                System.out.print("* ");
            }
            System.out.println();
        }
    }

4，打印菱形

 private static void fun4() {
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要打的边长数：");
        int a = sc.nextInt();
        //上部分
        for (int i = 1; i <= a; i++) {
    
    
            for (int j = 1; j <= a-i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j < i; j++) {
    
    
                System.out.print("* ");
            }
            System.out.println();
        }
        //下部分
        for (int i = 1; i <= a-1; i++) {
    
    
            for (int j = 1; j <=i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j <a-i; j++) {
    
    
                System.out.print("* ");
            }
            System.out.println();
        }

    }

5，打印空心菱形

//空心菱形
    private static void fun5() {
    
    
        Scanner sc = new Scanner(System.in);
        System.out.println("请输入你要打的边长数：");
        int a = sc.nextInt();
        for (int i = 1; i <= a; i++) {
    
    
            for (int j = 1; j <= a-i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j <= i; j++) {
    
    
                if (j==1||j==i){
    
    
                    System.out.print("* ");
                }else {
    
    
                    System.out.print("  ");
                }
            }
            System.out.println();
        }
        for (int i = 1; i <= a-1; i++) {
    
    
            for (int j = 1; j <=i; j++) {
    
    
                System.out.print(" ");
            }
            for (int j = 1; j <=a-i; j++) {
    
    
                if (j==1||j==a-i){
    
    
                    System.out.print("* ");
                }else {
    
    
                    System.out.print("  ");
                }
            }
            System.out.println();
        }

    }