java中的枚举类

枚举类中枚举值序号（类似于数组下标）默认从0开始。要获取它的下标可以调用ordinal()方法实现。

    public enum Days{
    Monday,
    Tuesday,
    Wednesday,
Thursday,
Friday,
Saturday,
Sunday;
}

    public static void main(String[] args) {
System.out.println(Days.Sunday.ordinal());
}

    2. 可以给枚举值添加各种属性，并且可以通过构造函数给枚举值赋予初始值，通过get,set方法更新枚举值的属性值。public enum OrderStatusEnum {
CANCELED(0, "已取消"),
NO_PAY(10,"未支付"),
PAID(20,"已付款"),
SHIPPED(40,"已发货"),
ORDER_SUCCESS(50,"订单完成"),
ORDER_CLOSE(60,"订单关闭");

private int code;
private String value;

OrderStatusEnum(int code, String value) {
this.code = code;
this.value = value;
}

public int getCode() {
return code;
}

public void setCode(int code) {
this.code = code;
}

public String getValue() {
return value;
}

public void setValue(String value) {
this.value = value;
}
}

    public static void main(String[] args) {
OrderStatusEnum.CANCELED.setCode(1);
System.out.println(OrderStatusEnum.CANCELED.getCode());
}

    3. 枚举类一般可以定义在常量类中，如Const类当中。