版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/u013317445/article/details/82352226
HashMap集合嵌套ArrayList集合
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Set;
/**
* @program: javalearnCode
* @description: HashMap集合嵌套ArrayList集合。
* @author: chen
* @create: 2018-09-03 11:34
**/
public class HashMapArrayListDemo {
public static void main(String[] args){
/*
假设HashMap有3个集合是ArrayList:
三国演义
诸葛亮
周瑜
红楼梦
黛玉
宝玉
西游记
悟空
唐僧
*/
//创建集合
HashMap<String, ArrayList<String>> novels= new HashMap<String, ArrayList<String>>();
ArrayList<String> sanGuoCharacters= new ArrayList<String>();
sanGuoCharacters.add("诸葛亮");
sanGuoCharacters.add("周瑜");
ArrayList<String> xiyoujiCharacters= new ArrayList<String>();
xiyoujiCharacters.add("悟空");
xiyoujiCharacters.add("唐僧");
ArrayList<String> hongloumengCharacters= new ArrayList<String>();
hongloumengCharacters.add("黛玉");
hongloumengCharacters.add("宝玉");
novels.put("三国演义", sanGuoCharacters);
novels.put("西游记", xiyoujiCharacters);
novels.put("红楼梦", hongloumengCharacters);
//遍历
Set<String> keys= novels.keySet();
for(String key: keys){
System.out.println(key);
ArrayList<String> characters=novels.get(key);
//遍历集合,List特有的遍历方式size()和get()结合
for(int i=0; i<characters.size(); ++i){
String character= characters.get(i);
System.out.println('\t'+character);
}
// 增强for遍历集合
// for(String character: characters){
// System.out.println(character);
// }
// 迭代器遍历集合
// Iterator<String> it= characters.iterator();
// while(it.hasNext()){
// String character= it.next();
// System.out.println(character);
// }
}
}
}
ArrayList集合嵌套HashMap集合
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Set;
/**
* @program: javalearnCode
* @description: ArrayList集合嵌套HashMap
* @author: chen
* @create: 2018-09-03 16:29
**/
public class ArraListHashMapDemo {
public static void main(String[] args){
//假设ArrayList有3个集合是HashMap
/*
吕布-貂蝉
周瑜-小乔
---------------
牛魔王-铁扇公主
玉帝-王母
---------------
贾琏-王熙凤
贾宝玉-薛宝钗
---------------
*/
//创建集合
ArrayList<HashMap<String, String>> array= new ArrayList<HashMap<String, String>>();
HashMap<String, String> sanguoCouples= new HashMap<String, String>();
sanguoCouples.put("周瑜","小乔");
sanguoCouples.put("吕布","貂蝉");
HashMap<String,String> xiyoujiCouples= new HashMap<String, String>();
xiyoujiCouples.put("牛魔王","铁扇公主");
xiyoujiCouples.put("玉帝","王母");
HashMap<String, String> hongloumengCouples= new HashMap<String, String>();
hongloumengCouples.put("贾琏","王熙凤");
hongloumengCouples.put("贾宝玉","薛宝钗");
array.add(sanguoCouples);
array.add(xiyoujiCouples);
array.add(hongloumengCouples);
//遍历集合
//获取ArrayList集合中每个HashMap元素
for(HashMap<String, String> couples: array){
//先获取所有键
Set<String> husbands=couples.keySet();
for(String husband: husbands){
//根据键获取值
String wife= couples.get(husband);
System.out.println(husband+"-"+wife);
}
System.out.println("---------------");
}
}
}