遍历set

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);}

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               }                ........  }