- package com.yang.mapdemo;
- import java.util.HashMap;
- import java.util.Iterator;
- import java.util.Map;
- import java.util.Map.Entry;
- public class MapDemo {
- public static void main(String[] args) {
- Map map = new HashMap();
- map.put("1", "first");
- map.put("2", "second");
- map.put("3", "third"); //1.通过Map.keySet遍历key和value for(String key : map.keySet()){ System.out.println("key="+key+", value="+map.get(key)); } //2.通过Map.entrySet使用iterator遍历key和value System.out.println("-------------------"); Iterator> it = map.entrySet().iterator(); while(it.hasNext()){ Entry entry = it.next(); System.out.println("key="+entry.getKey()+", value="+entry.getValue()); } //3.通过Map.entrySet遍历key和value(推荐,尤其是容量大时) System.out.println("-------------------"); for(Map.Entry entrySet : map.entrySet()){ System.out.println("key="+entrySet.getKey()+", value="+entrySet.getValue()); } //4.通过Map.values()遍历所有的value,但不能遍历key System.out.println("-------------------"); for(String a : map.values()){ System.out.println("value="+a); } }}
来源: http://www.92to.com/bangong/2017/05-22/22152243.html