Byte中一些面试题

 1 package q_2013_03_23;
 2 
 3 public class ByteDemo {
 4 
 5     public static void main(String[] args) {
 6 
 7 /*            byte b = 1+1;//对
 8               byte b = (byte) 128;
 9     1        System.out.println(b);//-128
10             
11 */
12         
13 /*            byte b = 1;
14     2        b = b + 1;//报错,因为b+1会自动转成int类型,然后再赋值给short类型,会精度丢失,所以报错
15                               char,byte,short参与运算会类型提升为int
16 */
17         
18 /*            byte b=1;
19     3        b += 1;//对,相当于 b = (byte)(b+1);
20             //b = (byte)(b+1);
21 */
22             
23 /*            byte b = 1;
24             b = ++b;
25             System.out.println(b);//对,2,在变量中自己自增    
26 */            
27             byte b = 1;
28             b = b ++;
29             System.out.println(b);//对,1
30 
31     }
32 
33 }

 

posted @ 2013-03-24 00:52  hacket520  阅读(139)  评论(0)    收藏  举报