UseHashMap

package com.shrimpking.t15;

import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;

/**
 * Created by IntelliJ IDEA.
 *
 * @Author : Shrimpking
 * @create 2024/9/10 21:06
 */
public class UseHashMap
{
    public static void main(String[] args)
    {
        Map<Integer,String> map = new HashMap<>();
        map.put(1,"one");
        map.put(2,"two");
        map.put(3,"three");
        map.put(4,"four");
        System.out.println(map);
        System.out.printf("key=%d, value=%s%n",3,map.get(3));

        Set<Integer> keys = map.keySet();
        System.out.println("映射中的键:");
        for (Integer key : keys){
            System.out.printf("%d\t",key);
        }
        System.out.println();

        Collection<String> values = map.values();
        System.out.println("映射中的值:");
        for (String value : values){
            System.out.printf("%s\t",value);
        }
        System.out.println();

        System.out.println("映射中的键值有:");
        Set<Map.Entry<Integer,String>> entries = map.entrySet();
        for (Map.Entry entry : entries){
            System.out.printf("%d:%s\t",entry.getKey(),entry.getValue());
        }
        System.out.println();

        System.out.println("遍历映射中的键值对:");
        map.forEach((k,v)-> System.out.printf("%d:%s\t",k,v));
    }
}