java容器的几种遍历

package cn.qyh.Collection;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;


public class TestIterator {
    public static void main(String[] args) {
        
        List<String> list = new ArrayList<String>();
             list.add("张三1");
             list.add("张三2");
             list.add("张三3");
             list.add("张三4");
        List<String> list2 = new LinkedList<String>();
            list2.add("李四1");
            list2.add("李四2");
            list2.add("李四3");
            list2.add("李四4");
        Map<Integer,String> map = new HashMap<Integer,String>();
            map.put(001, "张三");
            map.put(002, "李四");
            map.put(003, "王五");
            map.put(004, "赵六");
            
          //list中用while遍历
         Iterator<String> listIt = list.iterator();
         while(listIt.hasNext()){
             System.out.println(listIt.next());
         }
         System.out.println("#############");
        
         
         
         //用for遍历
         for(Iterator<String> link = list2.iterator();link.hasNext();) {
             System.out.println(link.next());
         }
         
         System.out.println("#############");

         
         //Map分别获得key和value
         for(Integer key:map.keySet()) {  //keyset获取key的值
             System.out.println(key);
         }
         for(String value :map.values()) { //values获取value的值
             System.out.println(value);
         }
         System.out.println("#############");
         
         
         //Map中key和value一起获得
         for(Map.Entry<Integer,String> entry:map.entrySet()) { //entry获取key和value    
             System.out.println(entry.getKey()+":"+entry.getValue());
             
         }
         System.out.println("#############");
         
         
         //Iterator 和    entryset获取key和value
         Iterator <Map.Entry<Integer,String>> it = map.entrySet().iterator();
         while(it.hasNext()) {
             Map.Entry<Integer, String> entry = it.next();
             System.out.println(entry.getKey()+"---"+entry.getValue());
             
         }
         
         
         
    }


}
我亦无他,惟手熟尔
原文地址:https://www.cnblogs.com/AsuraPlus/p/10613968.html