括号内的值的枚举 [英] Enums with values inside brackets

问题描述

嗨...



我在 http：// docs中看到过一些例子.oracle.com / [ ^ ]包含带有一些变量的枚举在每个enum对象里面，如下面的例子...

Hi...

Ive seen some examples in http://docs.oracle.com/[^] that contains enums with some variables inside each enum objects like the example below...

public enum Planet {
    MERCURY (3.303e+23, 2.4397e6),
    VENUS   (4.869e+24, 6.0518e6),
    EARTH   (5.976e+24, 6.37814e6),
    MARS    (6.421e+23, 3.3972e6),
    JUPITER (1.9e+27,   7.1492e7),
    SATURN  (5.688e+26, 6.0268e7),
    URANUS  (8.686e+25, 2.5559e7),
    NEPTUNE (1.024e+26, 2.4746e7);

    private final double mass;   // in kilograms
    private final double radius; // in meters
    Planet(double mass, double radius) {
        this.mass = mass;
        this.radius = radius;
    }

我试图创建一个类似的枚举..

And Ive tried to create an enum like the same..

public class EnumsWithValueInsideBracketsTest
{
    public static void main(String[] args)
    {

    }
    enum Days
    {
        Monday(false), Tuesday(false), Wednesday(false), Thursday(false), Friday(false), Saturday(true), Sunday(true)
    }
}

但程序没有运行，它说

But the program doesnt run and it says

constructor Days in enum Days cannot be applied to given types;
required: no argument
found: boolean
reason: actual and formal arguments lists differ in length"

这究竟是什么意思？



如何用布尔值创建一些枚举？

What does that really mean ?

And how can I create some enums with booleans values ?

推荐答案

这意味着你有没有在你的枚举中创建一个带有布尔值的构造函数。你需要改变它看起来像：

It means that you have not created a constructor in your enum which takes a boolean value. You need to change it so it looks like:

public enum Day
{
    Monday(false),
    Tuesday(false),
    Wednesday(false),
    Thursday(false),
    Friday(false),
    Saturday(true),
    Sunday(true);

    private final boolean weekEnd;

    Day(boolean weekEnd) {
        this.weekEnd = weekEnd;
    }
    bool isWeekend()
    {
        return weekEnd;
    }
}

固定类型为布尔

[/ edit]

[edit]
fixed type to boolean
[/edit]

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