I have enum
enum Number{
FIRST(123),
SECOND(321);
}
Number nr=Number.FIRST
How can I get an enum value (not a String but int ) from my variable nr without creating a new method?
3 Answers
In Java, enums are objects too. Provide a constructor for your numbers to be passed in, plus a public instance variable; no getter method necessary.
enum Num{
FIRST(123),
SECOND(321);
public final int value;
private Num(int value) { this.value = value; }
}
5 Comments
fge
Uhm, your integer is mutable here
rgettman
Sure, but the OP did state "without creating a new method".
Tim Bender
Eh, you can make it immutable without making it private. Fixed it for you.
Tim Bender
Also, +1 for the best (typically terrible) solution!
fge
Note, the
private modifier for the enum constructor is redundant, it is private by definitionYou need to write your enum like this (also, do not call it Number please! There is java.lang.Number):
enum MyNumber
{
FIRST(123),
SECOND(321);
private final int number;
MyNumber(final int number)
{
this.number = number;
}
public int getNumber()
{
return number;
}
}
If you don't want an accessor, remove the getter and make number public.
Comments
TL;DR: You can't.
Long version:
The code snippet you have above will not compile because you are missing the constructor:
private int value;
public Number(int i) {
this.value = i;
}
After you've done that, then you will need to provide the getter for value:
public int getValue() {
return this.value;
}
EDIT: If you really, really, don't want to create a new method, you can make the value field public, but you're violating the OO concept of encapsulation (ie, best practice).
3 Comments
Tim Bender
What name conflict? Java doesn't care if you name your class the same as another Class, so long as the fully qualified name is different.
fge
OK, but who on earth will import some.other.package.Number instead of java.lang.Number?
ryanprayogo
Well, if your client class is on the same package (ie,
some.other.package), then some.other.package.Number will be used instead of java.lang.Number unless you import java.lang.Number specifically.
0) or the number you have next toFIRSTin the declaration (123)?enumwon't compile. You need a constructor that takes anint. And you will need to create a method.