package com.yjf.esupplier.common.test; import java.util.HashMap; import java.util.Map; /** * @author shusheng * @description Map集合的使用 * @Email [email protected] * @date 2018/12/17 16:29 */ public class MapDemo1 { public static void main(String[] args) { // 创建集合 Map<String, String> map = new HashMap<String, String>(); //添加元素 System.out.println("map:" + map.put("文章", "马伊琍")); System.out.println("map:" + map.put("文章", "姚笛")); map.put("邓超", "孙俪"); map.put("黄晓明", "杨颖"); map.put("周杰伦", "昆凌"); map.put("刘恺威", "杨幂"); System.out.println("map:" + map); //长度 System.out.println("size:" + map.size()); //删除功能 System.out.println("remove:" + map.remove("黄晓明")); System.out.println("remove:" + map.remove("黄海波")); //判断功能 System.out.println("containsKey:" + map.containsKey("黄晓明")); System.out.println("containsKey:" + map.containsKey("周杰伦")); System.out.println("containsValue:" + map.containsValue("杨幂")); System.out.println("containsValue:" + map.containsValue("张三")); //删除功能 map.clear(); System.out.println("isEmpty:" + map.isEmpty()); //输出集合名称 System.out.println("map:" + map); } }
打印结果:
map:null map:马伊琍 map:{邓超=孙俪, 文章=姚笛, 周杰伦=昆凌, 黄晓明=杨颖, 刘恺威=杨幂} size:5 remove:杨颖 remove:null containsKey:false containsKey:true containsValue:true containsValue:false isEmpty:true map:{}