Java基础五

1 for(){//行
2   for(){//列
3 
4  }
5 }

1 for (int i=1;i<=9;i++){
2       for (int j=1;j<=i;j++){
3             System.out.print(i+"*"+j+"="+i*j+"\t");
4        }
5             System.out.println();
6         }

 1 //          *
 2 //          ***
 3 //          *****
 4 //          *******
 5 //          *********
 6 
 7         for (int i=1;i<=5;i++){
 8             for (int j=1;j<=2*i-1;j++){
 9                 System.out.print("*");
10             }
11             System.out.println();
12         }
13         System.out.println();

 1 //        ****
 2 //        ***
 3 //        **
 4 //        *
 5         
 6         for (int i=1;i<=4;i++){
 7             for (int j=5-i;j>0;j--){
 8                 System.out.print("*");
 9             }
10             System.out.println();
11         }
12 
13         System.out.println();

 1 //            *
 2 //           ***
 3 //          *****
 4 //         *******
 5 //        *********
 6 
 7         for (int i=1;i<=5;i++){
 8             for (int j=1;j<=i+4;j++) {
 9                 if (j<=5-i)
10                     System.out.print(" ");
11                 else
12                     System.out.print("*");
13             }
14             System.out.println();
15         }

 1 public class Test {
 2     public static void main(String[] args) {
 3         for (int i=1;i<=5;i++){
 4             for (int j=1;j<=4+i;j++){
 5                 if (j==6-i || j==4+i){
 6                     System.out.print("*");
 7                 }else {
 8                     System.out.print(" ");
 9                 }
10             }
11             System.out.println();
12         }
13         for (int i=1;i<=4;i++){
14             for (int j=1;j<=9-i;j++){
15                 if (j==i+1 || j==9-i){
16                     System.out.print("*");
17                 }else {
18                     System.out.print(" ");
19                 }
20             }
21             System.out.println();
22         }
23 
24 
25     }
26 }