前言

前几天敌人给我分享了一道很简略的校招面试题,我感觉还蛮有意思的,分享进去给你们做一下试一下,看你们做进去要花多久工夫!

题目

类的成员变量:
请定义一个交通工具(Vehicle)的类,其中有:属性:速度(speed),体积
(size)等等
办法:挪动(move()),设置速度(setSpeed(int speed)),减速speedUp(),减
速speedDown()等等.
最初在测试类Vehicle中的main()中实例化一个交通工具对象,并通过方
法给它初始化speed,size的值,并且通过打印进去。另外,调用减速,减
速的办法对速度进行扭转。

public class Vehicle {    private int speed;    private int size;    public Vehicle() {    }    public Vehicle(int speed, int size) {        this.speed = speed;        this.size = size;    }    //挪动    public void move(){ }    //减速    public void speedUp(int speed){        this.speed+=speed;    }    //加速    public void speedDown(int speed){        this.speed-=speed;    }    public int getSpeed() {        return speed;    }    public void setSpeed(int speed) {        this.speed = speed;    }    public int getSize() {        return size;    }    public void setSize(int size) {        this.size = size;    }    public static void main(String[] args) {       Vehicle vehicle = new Vehicle();        vehicle.setSpeed(160);        vehicle.setSize(100);        System.out.println("速度为:"+vehicle.getSpeed());        System.out.println("体积为:"+vehicle.getSize());        vehicle.speedUp(10);        System.out.println("减速为:"+vehicle.getSpeed());        vehicle.speedDown(100);        System.out.println("加速为:"+vehicle.getSpeed());    }}

后果为:

类的成员变量与办法、构造方法

在程序中,常常要对工夫进行操作,然而并没有工夫类型的数据。那
么,咱们能够本人实现一个工夫类,来满足程序中的须要。
定义名为MyTime的类,其中应有三个整型成员:时(hour),分
(minute),秒(second),为了保证数据的安全性,这三个成员变量
应申明为公有。 为MyTime类定义构造方法,以不便创建对象时初始化
成员变量。 再定义diaplay办法,用于将工夫信息打印进去。
为MyTime类增加以下办法:
addSecond(int sec)
addMinute(int min)
addHour(int hou)
subSecond(int sec)
subMinute(int min)
subHour(int hou)
别离对时、分、秒进行加减运算。
代码

public class MyTime {    private int hour;    private int minute;    private int second;    public MyTime(int hour, int minute, int second) {        this.hour = hour;        this.minute = minute;        this.second = second;    }    public void display() {        System.out.println("hour=" + hour +                ", minute=" + minute +                ", second=" + second +                '}');    }    public void addSecond(int sec){        this.second+=sec;    }    public void addMinute(int min){        this.minute+=min;    }    public void addHour(int hou){        this.hour+=hou;    }    public void subSecond(int sec){        this.second-=sec;    }    public void subMinute(int min){        this.minute-=min;    }    public void subHour(int hou){        this.hour-=hou;    }}

构造方法:

编写Java程序,用于显示人的姓名和年龄。定义一个人类(Person),
该类中应该有两个公有属性,姓名(name)和年龄(age)。定义结构
办法,用来初始化数据成员。再定义显示(display)办法,将姓名和年
龄打印进去。
代码:

public class Person {    private String name;    private int age;    public Person(String name, int age) {        this.name = name;        this.age = age;    }    public void display() {        System.out.println( "name='" + name + '\'' +                ", age=" + age);    }    public static void main(String[] args) {        Person yc = new Person("yc", 6);        yc.display();    }}

get办法和set办法

定义一个类,该类有一个公有成员变量,通过构造方法将其进行赋初
值,并提供该成员的getXXX()和setXXX()办法

public class Lab04 {    private int age;    public Lab04() {        age = 10;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    public static void main(String[] args) {        Lab04 lab04 = new Lab04();        System.out.println(lab04.getAge());    }}

构造方法与重载

建设一个汽车类,包含轮胎个数,汽车色彩,车身分量等属性。并通过
不同的构造方法创立事例。
至多要求:汽车可能减速,加速,停车。
要求:命名标准,代码体现档次,有敌对的操作提醒。

public class Car {    private int TiresNum;    private String color;    private double weight;    private int speed=30;    public Car() {    }    public Car(int tiresNum, String color, double weight) {        this.TiresNum = tiresNum;        this.color = color;        this.weight = weight;    }    //减速    public void speedUp(int speed){        System.out.println("汽车减速"+speed+"km/s");        this.speed+=speed;    }    //加速    public void speedDown(int speed){        System.out.println("汽车加速"+speed+"km/s");        this.speed-=speed;    }    public void stop(){       speed=0;        System.out.println("汽车停车");    }    //速度    public void carStatus(){        System.out.println("汽车以"+getSpeed()+"km/s的速度前行");    }    public int getTiresNum() {        return TiresNum;    }    public void setTiresNum(int tiresNum) {        TiresNum = tiresNum;    }    public String getColor() {        return color;    }    public void setColor(String color) {        this.color = color;    }    public double getWeight() {        return weight;    }    public void setWeight(double weight) {        this.weight = weight;    }    public int getSpeed() {        return speed;    }    public void setSpeed(int speed) {        this.speed = speed;    }    @Override    public String toString() {        return "Car" +                "轮胎数=" + TiresNum +                "个, 色彩='" + color + '\'' +                ", 分量=" + weight +                "kg, 速度=" + speed +                "km/s";    }}class CarTest{    public static void main(String[] args) {        Car car = new Car();        car.setTiresNum(4);        car.setColor("红色");        car.setWeight(100.1);        System.out.println(car.toString());        car.carStatus();        car.stop();        car.carStatus();        car.speedUp(100);        car.carStatus();        car.speedDown(20);        car.carStatus();        System.out.println("----------------------");        Car car1 = new Car(4, "彩色", 100.0);        car1.toString();        car.carStatus();        car.stop();        car.carStatus();        car.speedUp(180);        car.carStatus();        car.speedDown(30);        car.carStatus();    }}

后果为:

Static关键字与一般变量的区别:

创立一个名称为StaticDemo的类,并申明一个动态变量和一个一般变
量。对变量别离赋予10和5的初始值。在main()办法中输入变量值。

public class StaticDemo {    public static int num=10;    public int num1=5;    public static void main(String[] args) {        System.out.println("num="+StaticDemo.num);        StaticDemo staticDemo = new StaticDemo();        System.out.println("num1="+staticDemo.num1);    }}

后果为:

包、继承、构造函数

创立一个名称为MainPackage的包,使它蕴含MainClass和MainSubClass
类。MainClass类该当蕴含变量申明,其值从构造方法中输入。
MainSubClass类从MainClass派生而来。试执行下列操作:创立一个名称
为SamePackage的类,使它导入上述包,并创立一个MainSubClass类的对

package day06.MainPackage;public class MainClass {    int num=10;    public MainClass() {        System.out.println(num);    }}
package day06.MainPackage;public class MainSubClass extends MainClass {}
package day06;import day06.MainPackage.MainSubClass;public class SamePackage {    public static void main(String[] args) {        MainSubClass mainSubClass = new MainSubClass();    }}

后果:

笼罩、继承

建设一个汽车Auto类,包含轮胎个数,汽车色彩,车身分量、速度等成
员变量。并通过不同的构造方法创立实例。至多要求:汽车可能减速,
加速,停车。再定义一个小汽车类Car,继承Auto,并增加空调、CD等
成员变量,笼罩减速,加速的办法
Auto.java

public class Auto {    private int TiresNum;    private String color;    private double weight;    private int speed=30;    public Auto() {    }    public Auto(int tiresNum, String color, double weight) {        this.TiresNum = tiresNum;        this.color = color;        this.weight = weight;    }    //减速    public void speedUp(int speed){        System.out.println("汽车减速"+speed+"km/s");        this.speed+=speed;    }    //加速    public void speedDown(int speed){        System.out.println("汽车加速"+speed+"km/s");        this.speed-=speed;    }    public void stop(){        speed=0;        System.out.println("汽车停车");    }    public int getTiresNum() {        return TiresNum;    }    public void setTiresNum(int tiresNum) {        TiresNum = tiresNum;    }    public String getColor() {        return color;    }    public void setColor(String color) {        this.color = color;    }    public double getWeight() {        return weight;    }    public void setWeight(double weight) {        this.weight = weight;    }    public int getSpeed() {        return speed;    }    public void setSpeed(int speed) {        this.speed = speed;    }}

car.java

public class Car extends Auto{    private String airCondition;    private String cdName;    public Car() {    }    public Car(int tiresNum, String color, double weight, String airCondition, String cdName) {        super(tiresNum, color, weight);        this.airCondition = airCondition;        this.cdName = cdName;    }    @Override    public void speedUp(int speed) {        super.speedUp(speed);        System.out.println("我是小车减速");    }    @Override    public void speedDown(int speed) {        super.speedDown(speed);        System.out.println("我是小车加速");    }}

最初

不晓得你做进去花了多久的工夫呢,如果有什么不懂的和须要探讨的能够在评论区留言!