Java遍历Set集合方法

Posted 2022-01-06 Firm陈

对 set 的遍历  
  
1.迭代遍历：  
Set<String> set = new HashSet<String>();  
Iterator<String> it = set.iterator();  
while (it.hasNext())   
  String str = it.next();  
  System.out.println(str);  
  
  
2.for循环遍历：  
for (String str : set)   
      System.out.println(str);  
  
  
  
优点还体现在泛型 假如 set中存放的是Object  
  
Set<Object> set = new HashSet<Object>();  
for循环遍历：  
for (Object obj: set)   
      if(obj instanceof Integer)  
                int aa= (Integer)obj;  
             else if(obj instanceof String)  
               String aa = (String)obj  
               
              ........