(連載)Java基礎學習006

基礎面對象

##練習題時鐘#
package com.lovoinfo;

import java.util.Calendar;

/**
 * 時鐘
 * @author zenghao
 *
 */
public class Clock {

    private int hour;       // 時
    private int minute;     // 分
    private int second;     // 秒

    /**
     * 構造器
     */
    public Clock() {
        Calendar cal = Calendar.getInstance();
        hour = cal.get(Calendar.HOUR_OF_DAY);
        minute = cal.get(Calendar.MINUTE);
        second = cal.get(Calendar.SECOND);
    }

    /**
     * 構造器
     * @param hour 時
     * @param minute 分
     * @param second 秒
     */
    public Clock(int hour, int minute, int second) {
        this.hour = hour;
        this.minute = minute;
        this.second = second;
    }

    /**
     * 走字
     */
    public void go() {
        second += 1;
        if(second == 60) {
            second = 0;
            minute += 1;
            if(minute == 60) {
                minute = 0;
                hour += 1;
                if(hour == 24) {
                    hour = 0;
                }
            }
        }
    }

    /**
     * 顯示時間
     * @return 返回當前時間
     */
    public String display() {
        String str = "";
        if(hour < 10) {
            str += "0";
        }
        str += hour + ":";
        if(minute < 10) {
            str += "0";
        }
        str += minute + ":";
        if(second < 10) {
            str += "0";
        }
        str += second;
        return str;
    }

    /**
     * 調整小時
     * @param up true表示上調, false表示下調
     */
    public void setHour(boolean up) {
        if(up) {
            hour = (hour + 1) % 24;
        }
        else {
            hour -= 1;
            if(hour == -1) {
                hour = 23;
            }
        }
    }

    /**
     * 調整分鐘
     * @param up true表示上調, false表示下調
     */
    public void setMinute(boolean up) {
        if(up) {
            minute = (minute + 1) % 60;
        }
        else {
            minute -= 1;
            if(minute == -1) {
                minute = 59;
            }
        }
    }

    /**
     * 調整秒
     * @param up true表示上調, false表示下調
     */
    public void setSecond(boolean up) {
        if(up) {
            second = (second + 1) % 60;
        }
        else {
            second -= 1;
            if(second == -1) {
                second = 59;
            }
        }
    }
}

package com.lovoinfo;

import javax.swing.JOptionPane;

public class Test03 {

    public static void main(String[] args) throws InterruptedException {
        Clock c = new Clock();  // 用構造器創建時鐘對象
        JOptionPane.showMessageDialog(null, c.display());
        System.exit(0); // 關閉JVM
    }
}

手機

package com.lovoinfo;

/**
 * 手機
 * @author zenghao
 *
 */
public class MobilePhone {
    String brand;   // 品牌
    double screenSize;  // 屏幕尺寸
    boolean smart;  // 是不是智能機

    /**
     * 打電話
     * @param telNumber 呼叫的號碼
     */
    public void call(String telNumber) {
        System.out.println("正在呼叫" + telNumber);
    }

    /**
     * 發短信
     * @param telNumber 收信人
     * @param message 消息的內容
     */
    public void sendMsg(String telNumber, String message) {
        System.out.println("向" + telNumber + "發送...");
        System.out.println(message);
    }
}

package com.lovoinfo;


public class Test01 {

    public static void main(String[] args) {
        MobilePhone phone = new MobilePhone();
        phone.call("13812345678");
        phone.sendMsg("13900998877", "晚上一起吃飯吧?");
    }
}

學生

package com.lovoinfo;

/**
 * 學生
 * @author zenghao
 *
 */
public class Student {
    private String name;    // 姓名
    private int age;        // 年齡

    /**
     * 構造器
     * @param name 姓名
     * @param age 年齡
     */
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    /**
     * 吃飯
     * @param food 吃的東西
     */
    public void eat(String food) {
        System.out.println(name + "正在吃" + food);
    }

    /**
     * 睡覺
     */
    public void sleep() {
        System.out.println(name + "正在睡覺.");
    }

    /**
     * 學習
     * @param courseName 課程的名稱
     */
    public void study(String courseName) {
        System.out.println(name + "正在學習" + courseName);
    }

    @Override
    public String toString() {
        return name + " - " + age;
    }

}

package com.lovoinfo;

public class Test02 {

    public static void main(String[] args) {
        Student stu = new Student("王大錘", 20);
        stu.eat("牛肉麪");
        stu.sleep();
        stu.study("Java程序設計");

        System.out.println(stu);
    }
}

5.1作業：有一個游泳池我不知道它半徑，我要修一個3M寬的人行道，和圍牆。人行道修1平方要8元。圍牆1米5元。總共要多少資費。

  package com.lovoinfo;

public class Swim {
    double radii;

    public double Swin(double tariff) {
        double R = radii + 3;
        double money1 = ((R * R - radii * radii) * 3.14) * 8 + R * 3.14 * 5;

        return money1;
    }

}

package com.lovoinfo;

import java.util.Scanner;

public class Test001 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Swim circle = new Swim();
        System.out.println("半徑爲:");
        double Tariff = sc.nextDouble();
        System.out.println("總共需要花費：" + circle.Swin(Tariff)+"元");
        sc.close();
    }
}