Java正式day_04——嵌套循环

 

package com.situ.chapter;

import java.util.Scanner;

//1. 从控制台输入一个三角形高度，拼成一个菱形。
public class Subject02 {
    public static void main(String[] args) {
        System.out.println("请输入三角形的高度：");
        Scanner scanner = new Scanner(System.in);
        int height = scanner.nextInt();
        int i = 0;
        while (i < height) {
            int j = 0;
            while (j < height - i - 1) {
                System.out.print(" ");
                j++;
            }
            // 输出星号
            int k = 0;
            while (k < 2 * i + 1) {
                System.out.print("*");
                k++;
            }
            System.out.println();
            i++;
        }

        // 打印下半部分三角形
        // ***** 1 1 5
        // *** 2 2 3
        // * 3 3 1
        int m = 1;
        while (m <= height - 1) {
            int n = 1;
            while (n <= m) {
                System.out.print(" ");
                n++;
            }
            int l = 0;
            while (l <= 2 * (height - 1 - m)) {
                System.out.print("*");
                l++;
            }
            m++;
            System.out.println();
        }
        scanner.close();
    }
}