Regarding Enum access specifier

[sharma ishu]

Please explain what does this line means.

"The constructor for an enum type must be package-private or private access."

[Guillaume Jourdan]

This sentence means that you can't implement an enum outside the enum class definition. By default, an enum have a private default constructor, but you can define your own constructor.

Example :

public enum ColorHex {

WHITE("#ffffff"), BLACK("#000000"), RED("#ff0000"), GREEN("#00ff00"), BLUE("#0000ff");

private String colorHexaCode;
 
private ColorHex(String colorCode){
    colorHexaCode = colorCode;
}

public String getColorHexaCode() {
   return colorHexaCode ;
 }

}

[John Jai]

Please UseAMeaningfulSubjectLine henceforth. I have modified it for you this time.

[Matthew Brown]

And to add to what Guillaume said - try adding a constructor to the enum that has a public or protected modifier. You should get a compiler error.

To be honest, I'm not sure why they allow a package-accessible constructors as well as private, but it may be just so that you can get away with not giving a modifier.

[sharma ishu]

Matthew Brown wrote:And to add to what Guillaume said - try adding a constructor to the enum that has a public or protected modifier. You should get a compiler error.

To be honest, I'm not sure why they allow a package-accessible constructors as well as private, but it may be just so that you can get away with not giving a modifier.

But we cannot say like: new EnumType();
So, what difference does it make that what access modifier is used for the constructor.

[Matthew Brown]

sharma ishu wrote:But we cannot say like: new EnumType();
So, what difference does it make that what access modifier is used for the constructor.

Look at it the other way: since you can't go new EnumType(), what possible reason could there be to have a public or protected constructor? There's a general tendency in the design of Java to disallow things that don't make sense.

[RajaShekhar Gundeti]

It seems enums are used to declare a fixed set of meaningful constants. so, it doesn't allow creations of enums dynamically at runtime by restricting using access specifier. enums are static and compile.