Map遍歷的四種方式

package com.itcast.map;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;

/**
 * map遍歷
 * @author wangzewen
 *
 */
public class MapErgodic {

	/**
	 * 通過鍵集合的迭代器
	 * @param map
	 */
	public static void method1(Map<String,String> map){
		Iterator<String> it = map.keySet().iterator();
		while(it.hasNext()){
			String key = it.next();
			String value = map.get(key);
			System.out.println(key+"***"+value);
		}
	}
	
	/**
	 * 通過鍵的集合
	 * @param map
	 */
	public static void method2(Map<String,String> map){
		Set<String> keySet = map.keySet();
		for (String str : keySet) {
			System.out.println(str+"###"+map.get(str));
		}
	}
	
	/**
	 * 通過map實體，迭代器
	 * @param map
	 */
	public static void method3(Map<String,String> map){
		Iterator<Entry<String, String>> it = map.entrySet().iterator();
		while(it.hasNext()){
			Entry<String, String> next = it.next();
			System.out.println(next.getKey()+"^^^"+next.getValue());
		}
	}
	
	/**
	 * 通過遍歷map實體集合
	 * @param map
	 */
	public static void method4(Map<String,String> map){
		Set<Entry<String, String>> entrySet = map.entrySet();
		for (Entry<String, String> entry : entrySet) {
			System.out.println(entry.getKey()+"$$$"+entry.getValue());
		}
	}
	
	public static void main(String[] args) {
		Map<String,String> map = new HashMap<String, String>();
		map.put("1", "001");
		map.put("2", "002");
		map.put("3", "003");
		map.put("4", "004");
		map.put("5", "005");
		
		//method1(map);
		//method2(map);
		//method3(map);
		method4(map);
	}
	
}