day09_三角形图案_99乘法表

三角形图案

public class TriangleDemo 
{
    public static void main(String[] args) 
    {
        /*
            输出三角形图案
        */
        //SB版
        //System.out.println("☆");
        //System.out.println("☆☆");
        //System.out.println("☆☆☆");
        //System.out.println("☆☆☆☆");
        //System.out.println("☆☆☆☆☆");
        
        //2B版
        /*int j = 1;
        for (int i = 1;i <= j;i ++ )
        {
            System.out.println("☆");
        }
        j ++;
        for (int i = 1;i <= j;i ++ )
        {
            System.out.print("☆");
        }
        System.out.println();
        j ++;
        for (int i = 1;i <= j;i ++ )
        {
            System.out.print("☆");
        }
        System.out.println();
        j ++;
        for (int i = 1;i <= j;i ++ )
        {
            System.out.print("☆");
        }
        System.out.println();
        j ++;
        for (int i = 1;i <= j;i ++ )
        {
            System.out.print("☆");
        }
        */
        
        //优化版
        
        for (int j = 1;j <= 5 ; j ++ )
        {
            for (int i = 1;i <= j;i ++ )
            {
                System.out.print("☆");
            }
            System.out.println();
        }
        
    }
}

99乘法表

public class Table99Demo 
//输出99乘法表
/*
System.out.println(1*1=1);
System.out.println(1*2=2 2*2=4);
System.out.println(1*3=3 2*3=6 3*3=9);
*/
//规律:第二个乘数和行数相同,第一个乘数<=第二个乘数
{
    public static void main(String[] args) 
    {
            //2B版
        /*
        int j = 1;
        for (int i =1;i <= j   ;i ++ )
        {
            System.out.print(i + "*" + j + "=" + (i * j));
        }
        System.out.println();
        j ++;
        for (int i =1;i <= j   ;i ++ )
        {
            System.out.print(i + "*" + j + "=" + (i * j) + " ");
        }
        System.out.println();
        j ++;
        for (int i =1;i <= j   ;i ++ )
        {
            System.out.print(i + "*" + j + "=" + (i * j) + " ");
        }
        System.out.println();
        */
        //优化版
        for (int j = 1;j <= 9 ;j ++ )
        {
            for (int i =1;i <= j;i ++ )
            {
                System.out.print(i + "*" + j + "=" + (i * j) + " ");
            }
            System.out.println();
        }
    }
}