java 中 enum 枚举的使用

package test3;

public final class Program {
    public static void main(String[] args) {
       // System.out.println(State.ON);
      //  System.out.println(State.OFF);
        System.out.println( Color.getName(1));
        Light[] allLight = Light.values();  
        
        for (Light aLight : allLight) {  
 
            System.out.println("当前灯name：" + aLight.name());  
 
            System.out.println("当前灯ordinal：" + aLight.ordinal());  
 
            System.out.println("当前灯：" + aLight);  
 
        }  
        for (State item : State.values()) {
            System.out.println(item);
            System.out.println(State.valueOf(item.name()));
        }
    }
}

enum State {
    ON(1), OFF(0);

int value = 1;

State(int value) {
        this.value = value;
    }
}

enum Light {  
      
    // 利用构造函数传参

RED(1), GREEN(3), YELLOW(2);

// 定义私有变量

private int nCode;

// 构造函数，枚举类型只能为私有

private Light(int _nCode) {

this.nCode = _nCode;

}

@Override  
    public String toString() {

return String.valueOf(this.nCode);

}

}

enum Color {  
    RED("红色", 1), GREEN("绿色", 2), BLANK("白色", 3), YELLO("黄色", 4);  
    // 成员变量  
    private String name;  
    private int index;

// 构造方法  
    private Color(String name, int index) {  
        this.name = name;  
        this.index = index;  
    }

// 普通方法  
    public static String getName(int index) {  
        for (Color c : Color.values()) {  
            if (c.getIndex() == index) {  
                return c.name;  
            }  
        }  
        return null;  
    }

// get set 方法  
    public String getName() {  
        return name;  
    }

public void setName(String name) {  
        this.name = name;  
    }

public int getIndex() {  
        return index;  
    }

public void setIndex(int index) {  
        this.index = index;  
    }  
}