map简单使用

package lianxii;

import java.util.HashMap;
import java.util.Map;

public class MapExp {

    public static void main(String[] args) {

        //        String s = "";一般字符串定义成这样
        //        String p1 = null;对象一般定义成这样
        String s1 = "p";
        Map<String, Object> map = new HashMap<String, Object>();//Object型是很多类型都可以
        map.put(s1, 7);
        map.put("user", "name");
        map.put("ll", false);
        Object a1 = map.get(s1);
        Object a2 = map.get("user");
        Object a3 = map.get("ll");
        System.out.println("a1=" + a1 + "\na2=" + a2 + "\na3=" + a3);

    }

}

//输出结果
//a1=7
//a2=name
//a3=false