Iterator的使用
List<String> list = new ArrayList<>();
Iterator<String> it = list.iterator();
while(it. hasNext()){
String obj = it. next();
System. out. println(obj);
}
List<String> list = new ArrayList<>();
Iterator<String> it = list.iterator();
while(it. hasNext()){
String obj = it. next();
System. out. println(obj);
}