1 public class TestFor19{
 2     public static void main(String [] args){
 3         int size =32;
 4         int startNum=size/2+1;
 5         int endNum=size/2+1;
 6         boolean flag = true;
 7         for(int j=1;j<=size;j++){
 8             for(int i=1;i<=size;i++){
 9                 if(i==startNum||i==endNum){//前面为空心菱形，//i>=startNum&&i<=endNum实心菱形
10                     System.out.print("*");
11                 }else{
12                     System.out.print(" ");
13                 }
14             
15             }
16         System.out.println();
17         if(endNum==size){
18             flag=false;
19         }
20         if(flag){//flag是true相当于在菱形的上班层
21             startNum--;
22             endNum++;    
23         }else{
24             startNum++;
25             endNum--;
26         }
27         
28         }
29         
30     }
31     
32 }