import java.util.ArrayList;

import java.util.HashMap;



public class Test {



	public static void main(String[] args) {

		ArrayList<String> strList = new ArrayList<String>();

		HashMap<String, String>  strMap = new HashMap<String, String>();

		strMap.put("1", "tt1");

		strMap.put("2", "tt2");

		strMap.put("3", "tt3");

		strMap.put("4", "tt4");

		strList.add("1");

		strList.add("2");

		strList.add("3");

		strList.add("4");

		//两个比较哪个快 TODO

		if(strMap.containsKey("4")){

			System.out.println("HashMap-->"+strMap.get("4"));

		}

		for (String string : strList) {

			if(string.equals("4")){

				System.out.println("ArrayList-->"+string);

			}

		}



	}

}