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java129-hashmap的方法

作者:互联网


import java.util.Date;
public class Car {
    private String brand;//品牌
    private Date createDate;
    private int housepower;//马力
    private int speed;//速度
    public void setBrand(String brand) {
        this.brand = brand;
    }
    public String getBrand() {
        return brand;
    }
    public Date getCreateDate() {
        return createDate;
    }
    public void setCreateDate(Date createDate) {
        this.createDate = createDate;
    }
    public void setHousepower(int housepower) {
        this.housepower = housepower;
    }
    public int getHousepower() {
        return housepower;
    }
    public void setSpeed(int speed) {
        this.speed = speed;
    }
    public int getSpeed() {
        return speed;
    }
}
测试类

import java.util.*;
 
public class test68 {
    public static void main(String[] args) {
        Car c0 = new Car();
        c0.setBrand("宝马");
        c0.setCreateDate(new Date());
        c0.setHousepower(4);
        c0.setSpeed(200);
 
        Car c1 = new Car();
        c1.setBrand("创奇");
        c1.setCreateDate(new Date());
        c1.setHousepower(5);
        c1.setSpeed(220);
 
        Car c2 = new Car();
        c2.setBrand("发力");
        c2.setCreateDate(new Date());
        c2.setHousepower(4);
        c2.setSpeed(240);
 
        Car c3 = new Car();
        c3.setBrand("丰田");
        c3.setCreateDate(new Date());
        c3.setHousepower(4);
        c3.setSpeed(230);
 
        //Car c4 = c3;
       // c4.setBrand("大众");
        //c4.setCreateDate(new Date());
        //c4.setHousepower(4);
        //c4.setSpeed(230);
        //添加hashmap的对象
        Map carMap = new HashMap();
        //使用put添加对象
        carMap.put("k1", c0);
        carMap.put("k2", c1);
        carMap.put("k3", c2);
        carMap.put("k4", c3);
        //carMap.put("k4",c4);
        //使用get返回自己需要的值
        Object obj = carMap.get("k4");
        if (obj != null) {
            Car target = (Car) obj;
            System.out.println(target.getBrand() + target.getHousepower());
        } else {
            System.out.println("未找到");
        }
        /*获取map集合的所有值*/
        Set keySet = carMap.keySet();
        Car c = null;
        for (Object k : keySet) {
            Car temp = (Car) carMap.get(k);
            System.out.println(temp.getBrand() + temp.getHousepower() + temp.getSpeed());
        }
        /*获取所有值对象*/
        Collection coll = carMap.values();
        for (Object v : coll) {
            System.out.println(((Car) v).getBrand());
        }
        /*判断是否包含某个给定的key*/
        boolean boo = carMap.containsKey("k9");
        System.out.println("是否包含k9" + boo);
        System.out.println(carMap.containsValue(c3));
 
        /*移除键值对象*/
        if (carMap.containsKey("k3")) {
            Object removeobj = carMap.remove("k3");
            System.out.println(((Car) removeobj).getBrand());
 
        }
        System.out.println(carMap.size());
    }
}
运行结果

 

标签:hashmap,Car,java129,println,Date,new,方法,public,carMap
来源: https://www.cnblogs.com/yao-655442/p/16411686.html