Java:label的使用（while循环）

 1 package java_test;
 2 
 3 public class labelWhile {
 4 
 5     public static void main(String[] args) {
 6         int i = 0;
 7         outer: while (true) {
 8             System.out.println("Outer while loop");
 9             while (true) {
10                 i++;
11                 System.out.println("i= " + i);
12                 if (i == 1) {
13                     System.out.println("continue");
14                     continue;
15                 }
16                 if (i == 3) {
17                     System.out.println("continue outer");
18                     continue outer;
19                 }
20                 if (i == 5) {
21                     System.out.println("break");
22                     break;
23                 }
24                 if (i == 7) {
25                     System.out.println("break outer");
26                     break outer;
27                 }
28             }
29         }
30     }
31 }

输出

 1 Outer while loop
 2 i= 1
 3 continue
 4 i= 2
 5 i= 3
 6 continue outer
 7 Outer while loop
 8 i= 4
 9 i= 5
10 break
11 Outer while loop
12 i= 6
13 i= 7
14 break outer

It is important to remember that the only reason to use labels in Java is when you have nested loops and you want to break or continue throught more the one nested level.