疊代器周遊List Set Map

- 
- package cn.sxt.collection;
- 
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.HashSet;
- import java.util.Iterator;
- import java.util.List;
- import java.util.Map;
- import java.util.Map.Entry;
- import java.util.Set;
- 
 測試疊代器周遊List、Set、Map



 public class TestIterator {
 	public static void main(String[] args) {
 		testIteratorList();
 
	testIteratorSet();
 		testIteratorMap();
		
		testRemove();
	}
	
 	public static void testIteratorList(){
 		List<String>  list = new ArrayList<>();
 		list.add("aa");
 		list.add("bb");
 		list.add("cc");



		//使用iterator周遊List

           

for(Iterator<String> iter=list.iterator();iter.hasNext();){
			String  temp = iter.next();
			System.out.println(temp);
		}
		
	}
	
	public static void testIteratorSet(){
		Set<String>  set = new HashSet<>();
		set.add("aa");
		set.add("bb");
		set.add("cc");
           

//使用iterator周遊Set
	for(Iterator<String> iter=set.iterator();iter.hasNext();){
		String  temp = iter.next();
		System.out.println(temp);
	}
	
}

public static void testIteratorMap(){
	Map<Integer,String> map1 = new HashMap<>();
	map1.put(100, "aa");
	map1.put(200, "bb");
	map1.put(300, "cc");
	

	//第一種周遊Map的方式
	Set<Entry<Integer,String>>  ss =  map1.entrySet();
	for(Iterator<Entry<Integer,String>> iter=ss.iterator();iter.hasNext();){
		Entry<Integer,String> temp = iter.next();
		
		System.out.println(temp.getKey()+"--"+temp.getValue());
		
	}
	System.out.println("++++++++++++++++++++++++");
	//第二種周遊Map的方式
	Set<Integer>  keySet = map1.keySet();
	for(Iterator<Integer> iter=keySet.iterator();iter.hasNext(); ){
		Integer key = iter.next();
		System.out.println(key+"----"+map1.get(key));
	}
           

}
	
- 	//測試邊周遊，邊删除
- 	public static void testRemove(){
- 		List<String> list = new ArrayList<>();
- 		for(int i=0;i<20;i++){
- 			list.add("gao"+i);
- 		}
-
           

for(int i=0;i<list.size();i++){
		String temp = list.get(i);
		if(temp.endsWith("2")){
			list.remove(i);
		}
		System.out.println(list.size()); 
		System.out.println(list.get(i));  
	}
	
	
}
           

}