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);

}

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 }

........

}