枚举类练习

练习一

案例：使用枚举类实现单例模式

package chapter08_oop3_teacher.src.com.atguigu10._enum.exer1;

/**
 * ClassName: BankTest1
 * Description:
 *
 * @Author 尚硅谷-宋红康
 * @Create 15:05
 * @Version 1.0
 */
public class BankTest1 {
    public static void main(String[] args) {
//        Bank1.instance = null;

        System.out.println(GirlFriend.XIAO_LI);
    }
}

//jdk5.0之前的使用枚举类定义单例模式
class Bank1{

    private Bank1(){}

    public static final Bank1 instance = new Bank1();


}
//jdk5.0使用enum关键字定义枚举类的方式定义单例模式
enum Bank2{
    CPB;
}

enum GirlFriend{

    XIAO_LI(20);

    private final int age;

    private GirlFriend(int age){
        this.age = age;
    }

}

练习二

案例：颜色枚举类Color(使用enum声明)

1、声明颜色枚举类：7个常量对象：RED, ORANGE, YELLOW, GREEN, CYAN, BLUE,PURPLE;

2、在测试类中，使用枚举类，获取绿色对象，并打印对象。

package chapter08_oop3_teacher.src.com.atguigu10._enum.exer2;

/**
 * ClassName: Color
 * Description:
 *
 * @Author 尚硅谷-宋红康
 * @Create 15:12
 * @Version 1.0
 */
public enum Color {
    RED, ORANGE, YELLOW, GREEN, CYAN, BLUE,PURPLE;
}

练习三

案例拓展：颜色枚举类(使用enum声明)
（1）声明颜色枚举类Color：

- 声明final修饰的int类型的属性red,green,blue
- 声明final修饰的String类型的属性description
- 声明有参构造器Color(int red, int green, int blue,String description)
- 创建7个常量对象：红、橙、黄、绿、青、蓝、紫，
- 重写toString方法，例如：RED(255,0,0)->红色

（2）在测试类中，使用枚举类，获取绿色对象，并打印对象。

提示：
- 7个常量对象的RGB值如下：
红：(255,0,0)
橙：(255,128,0)
黄：(255,255,0)
绿：(0,255,0)
青：(0,255,255)
蓝：(0,0,255)
紫：(128,0,255)

7个常量对象名如下：
RED, ORANGE, YELLOW, GREEN, CYAN, BLUE,PURPLE

package chapter08_oop3_teacher.src.com.atguigu10._enum.exer3;

/**
 * ClassName: ColorTest
 * Description:
 *
 * @Author 尚硅谷-宋红康
 * @Create 15:14
 * @Version 1.0
 */
public class ColorTest {
    public static void main(String[] args) {
        System.out.println(Color.GREEN);
    }
}

enum Color{
    RED(255,0,0,"红色"),
    ORANGE(255,128,0,"橙色"),
    YELLOW(255,255,0,"黄色"),
    GREEN(0,255,0,"绿色"),
    CYAN(0,255,255,"青色"),
    BLUE(0,0,255,"蓝色"),
    PURPLE(128,0,255,"紫色");

    private final int red;
    private final int green;
    private final int blue;
    private final String description;//颜色的描述

    Color(int red, int green, int blue, String description) {
        this.red = red;
        this.green = green;
        this.blue = blue;
        this.description = description;
    }

    public int getRed() {
        return red;
    }

    public int getGreen() {
        return green;
    }

    public int getBlue() {
        return blue;
    }

    public String getDescription() {
        return description;
    }

    @Override
    public String toString() {
//        return name() + "(" + red + "," + green + "," + blue + ")->" + description;
        return super.toString() + "(" + red + "," + green + "," + blue + ")->" + description;
    }
}