map作业三(集合)韩顺平

map作业三

package cn.usts.edu.homework;

import java.util.*;

/**
 * @author ：fly
 * @description:
 * @date ：2021/11/4 13:06
 */
public class EmployeeDemo {
    
    
    public static void main(String[] args) {
    
    
        Map m = new HashMap();
        m.put("jack",650);
        m.put("tom",1200);
        m.put("smith",2900);

        System.out.println("=========for遍历=========");
        Set keySet = m.keySet();
        for (Object key : keySet) {
    
    
            int sal =(int) m.get(key);
            System.out.println(key+"---"+sal+"元");
        }


        // entrySet遍历
        System.out.println("=========entrySet迭代器遍历=========");
        Set entrySet = m.entrySet();
        Iterator iterator = entrySet.iterator();
        while (iterator.hasNext()){
    
    
            Map.Entry next = (Map.Entry) iterator.next();
            System.out.println(next.getKey()+"---"+next.getValue()+"元");
        }

        System.out.println("=========修改jack=========");
        m.replace("jack",2600);
        m.forEach((key,value)-> System.out.println(key+"---"+value+"元"));
        // m.put("jack",26000);

        System.out.println("=========+100=========");
        m.forEach((key,value)->{
    
    m.replace(key,(int)value+100);});
        m.forEach((key,value)-> System.out.println(key+"---"+value+"元"));


        System.out.println("=========遍历工资=========");
        Collection values = m.values();
        for (Object value : values) {
    
    
            System.out.println("工资:"+value);
        }
    }

}