Java基础--for循环使用（打印三角形、九九乘法表）

class xTest{
	public static void main(String[] args) {
		for (int i = 1;i < 5;i++) {
			for (int y = 0;y<i;y++) {
				System.out.print("*");
			}
			System.out.println();
		}
		
		System.out.println("-------------------------------\n");
		for (int i = 1;i<=5;i++) {
			for (int z = 1;z<=i;z++) {
				System.out.print(z);
			}
			System.out.println();
		}
		
		System.out.println("-------------------------------\n");
		for (int i = 1;i <= 5;i++) {
			for (int y = 1;y<=i;y++) {
				System.out.print(" ");//控制行空白处空格
			}
			for (int a = i;a<=5;a++) {
				System.out.print("*");//控制列"*"
				System.out.print(" ");
			}
			System.out.println();
		}
		
		System.out.println("-------------------------------\n");	
		for (int i = 1;i<=9;i++) {
			for (int y = 1;y<=i;y++) {
				System.out.print(y+"*"+i+"="+i*y);
				System.out.print(" ");
			}
			System.out.println("\n");
		}
	}
}

运行结果：
*
**
***
****
-------------------------------
1
12
123
1234
12345
-------------------------------
 * * * * *
  * * * *
   * * *
    * *
     *
-------------------------------
1*1=1
1*2=2 2*2=4
1*3=3 2*3=6 3*3=9
1*4=4 2*4=8 3*4=12 4*4=16
1*5=5 2*5=10 3*5=15 4*5=20 5*5=25
1*6=6 2*6=12 3*6=18 4*6=24 5*6=30 6*6=36
1*7=7 2*7=14 3*7=21 4*7=28 5*7=35 6*7=42 7*7=49
1*8=8 2*8=16 3*8=24 4*8=32 5*8=40 6*8=48 7*8=56 8*8=64
1*9=9 2*9=18 3*9=27 4*9=36 5*9=45 6*9=54 7*9=63 8*9=72 9*9=81