public class TestIterator{
public static void main(String[] args){
testIteratorList();
testIteratorSet();
testIteratorMap();
}
//List
public static void testIteratorList(){
List<String> list = new ArrayList<>();
list.add("think");
list.add("yourself");
list.add("day by day!");
//首先获得迭代器
//使用Iterator遍历List
for(Iterator<String> iter=list.iterator();iter.hasNex();){
String temp = iter.next();
System.out.println(temp)
}
}
//Set
public static void testIteratorSet(){
Set<String> set = new HashSet<>();
set.add("think");
set.add("yourself");
set.add("day by day!");
//首先获得迭代器
//使用Iterator遍历Set
for(Iterator<String> iter=set.iterator();iter.hasNex();){
String temp = iter.next();
System.out.println(temp)
}
}
public static void testIteratorMap(){
Map<Integer,String> map = new HashMap<>();
map.put(1, "think");
map.put(2, "yourself");
map.put(3, "day by day!");
//首先获得迭代器
//使用Iterator遍历Map
Set<Entry<Integer,String>> ss = map.entrySet();
for(Iterator<Entry<Integer,String>> iter = ss.iterator();iter.hashNext();){
Entry<Integer,String> temp = iter.next();
System.out.println(temp.getKey()+"--"+temp.Value());
}
}
}
遍历容器方法总结
遍历List
方法一:普通for循环
for(int i=;i<list.size();i++){
String temp = (Sting)list.get(i)
System.out.println(temp);
}
t方法二:增强for循环(使用泛型)
for(String temp : list){
System.out.println(temp);
}
方法三:使用Iteratord迭代器(1)
for(Iterator<String> iter=set.iterator();iter.hasNex();){
String temp = iter.next();
System.out.println(temp)
}
方法四:使用Iteratord迭代器(2)
Iterator iter = list.iterator();
while(iter.hashNext()) {
Object obj = iter.next();
iter.remove();
System.out.println(obj);
}
遍历Set
方法一:增强for循环
for(String temp:set){
System.out.println(temp);
}
方法二:使用Iterator迭代器
for(Iterator<String> iter=set.iterator();iter.hasNex();){
String temp = iter.next();
System.out.println(temp)
}
遍历Map
方法一:根据Key获取Value
Map<Interger, Man> maps = new HashMap<Integer, Map>();
Set<Integer> keySet = maps.keySet();
for(Integer id : keySet){
System.out.println(map.get(id.name));
}
方法二:使用entrySet
Set<Entry<Integer,String>> ss = map.entrySet();
for(Iterator<Entry<Integer,String>> iter = ss.iterator();iter.hashNext();){
Entry<Integer,String> temp = iter.next();
System.out.println(temp.getKey()+"--"+temp.Value());
}