java 遍历 java遍历set集合

1 对 set 的遍历  
 2   
 3 1.迭代遍历：  
 4 Set<String> set = new HashSet<String>();  
 5 Iterator<String> it = set.iterator();  
 6 while (it.hasNext()) {  
 7   String str = it.next();  
 8   System.out.println(str);  
 9 }  
10   
11 2.增强or循环遍历：  
12 for (String str : set) {  
13       System.out.println(str);  
14 }  
15   
16   
17 3.优点还体现在泛型 假如 set中存放的是Object  
18   
19 Set<Object> set = new HashSet<Object>();  
20 for循环遍历：  
21 for (Object obj: set) {  
22       if(obj instanceof Integer){  
23                 int aa= (Integer)obj;  
24              }else if(obj instanceof String){  
25                String aa = (String)obj  
26              }  
27               ........  
28 }