Java-03流程控制

1、循环结构

2、条件语句

3、switch case

4、实例
打印九乘九乘法表

public class Main {
    public static void main(String[] args) {
        for (int j = 1; j <=9; j++) {
            for (int i = 1; i <= j; i++) {
                System.out.print(i+ "*" + j + "=" + j*i+"\t");
            }
            System.out.println();
        }

    }
}

打印三角形

public class Main {
    public static void main(String[] args) {
        //for循环打印三角形
        for (int i = 1; i <=5; i++) {
            for (int j = 5; j>=i; j--) {
                System.out.print(" ");
            }
            for (int j= 1;  j<= i; j++) {
                System.out.print("3");
            }
            for (int j = 1; j<=i; j++) {
                System.out.print("3");
            }
            System.out.println();//换行打印

        }
    }
}