java集合set遍历方法

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 (Object obj: set) {
    if(obj instanceof Integer){
        int aa= (Integer)obj;
    }else if(obj instanceof String){
        String aa = (String)obj
    }
    ........
}