在 Java 中对列表进行排序后，如何访问第一个元素？

Question

我创建了一个类 Car，具有这些属性和方法。我使用了一个列表来存储多个对象。

package com.company;
import java.util.ArrayList;
import java.util.Collections;

class Car implements Comparable<Car> {
    private String manufacturer;
    private int speed;
    private double price;
    private int year; // manufacture year

    public Car(String manufacturer, int speed, double price, int year) {
        this.manufacturer = manufacturer;
        this.speed = speed;
        this.price = price;
        this.year = year;
    }

    public String getManufacturer() {
        return manufacturer;
    }

    public int getSpeed() {
        return speed;
    }

    public double getPrice() {
        return price;
    }

    public int getYear() {
        return year;
    }

    public String toString() {
        return this.manufacturer + ", speed: " + this.speed + "km/h, price: " + this.price + " USD, year: " + this.year;
    }


    public int compareTo(Car c) {
        if (this.price == c.price)
            return 0;
        else if(this.price > c.price)
            return 1;
        else
            return -1;

    }
}

public class Solution {
    public static void main(String[] args) {
        List<Car> cars = new ArrayList<Car>();
        cars.add(new Car("Audi", 280, 35300, 2018));
        cars.add(new Car("Mercedes-Benz", 155, 80000, 2009));
        cars.add(new Car("Toyota", 155, 18750, 2011));
        cars.add(new Car ("Fiat", 140, 22500, 2000));
        cars.add(new Car ("Land Rover", 209, 90900, 2014));
         for (Car iterator: cars) {
            System.out.println(iterator);
        }

         Collections.sort(cars);
         for (Car iterator: cars) {
             System.out.println(iterator.getPrice());
         }
    }
}

使用 Comparable 接口后，我想访问排序列表的第一个元素，例如，因为我想获得最便宜的汽车。我怎么能那样做？

Answer 1

因为ArrayList您可以通过这种方式访问​​第一个元素：

cars.get(0);

对于LinkedList：

cars.getFirst();