java for循环嵌套的整理与优化 用*画图和99乘法表的两种形式

package MyDay05;

public class 练习1 {
    public static void main(String[] args) {
        for (int i = 0; i <4 ; i++) {
            for (int j = 0; j <4; j++) {
                System.out.print("*");
            }
            System.out.println();

        }
        System.out.println("----------");

        for (int i = 0; i <5 ; i++) {
            for (int j = 0; j i; j--) {
                System.out.print("*");
            }
            System.out.println();

        }
        System.out.println("-----------");
        for (int i = 0; i <5 ; i++) {
            for (int j = 0; j i ; j--) {
                System.out.print("*");
            }
            System.out.println();
        }
        System.out.println("------------");
        for (int i = 0; i <4 ; i++) {
            for (int j = 3; j >i ; j--) {
                System.out.print(" ");
            }
            for (int j = 0; j i ; j--) {
                System.out.print(" ");
            }

            for (int j = 0; j i*2; j--) {
                if(i==0||i==3||j==7||j==i*2+1){
                    System.out.print("*");
                }else {
                    System.out.print(" ");
                }
            }
            System.out.println();

        }
        System.out.println("-----------");
        for (int i = 1; i <=9 ; i++) {
            for (int j = 1; j <=i; j++) {

                System.out.print(j+"X"+i+"="+(i*j)+"t");
            }
            System.out.println();
        }
        System.out.println("-----------");
        for (int i = 1; i <=9 ; i++) {
            for (int j = 1; j