Constructor Enum error

Question

public enum ProductCategory {
  FOOD, BEVERAGE, DEFAULT;

private final String label;

private ProductCategory(String label){
this.label = label;
}

public String getLabel(){
        return label;
}

I want to implement method getLabel() in this enum class, but I am gettin error: "The constructor ProductCategory() is undefined".

I already have constructor that I need, what else I need to write? I tried to write default constructor but again I am getting error.

P.S. I am total beginner in java.

as a side note specifying an enum constructor as `private` is redundant. — Ousmane D., May 19 '17 at 17:19
Possible duplicate of [How can I declare enums using java](http://stackoverflow.com/questions/7007137/how-can-i-declare-enums-using-java) — Yahya, May 19 '17 at 17:20
One cannot write a default constructor. The default constructor is the one provided by the compiler for a class that has no constructor written. — Lew Bloch, May 19 '17 at 18:24

score 3 · Answer 1 · answered May 19 '17 at 17:17

3

The error is coming from declaration of enum members: since the constructor takes String label, you need to supply the string to pass to that constructor:

FOOD("food"), BEVERAGE("bev"), DEFAULT("[default]");

answered May 19 '17 at 17:17

Sergey Kalinichenko

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score 1 · Answer 2 · answered May 19 '17 at 17:18

The only constructor you've currently got requires a string to be passed in - but all the enum values (FOOD, BEVERAGE, DEFAULT) don't specify strings, so they can't call the constructor.

Two options:

Add a parameterless constructor:
```
private ProductCategory() {}
```
This wouldn't associate labels with your enum values though.

Specify the label on each value:

FOOD("Food"), BEVERAGE("Beverage"), DEFAULT("Default");

The latter is almost certainly what you want.

score 0 · Answer 3 · answered May 19 '17 at 17:22

Enum constructor can be called while declaring the Enum members itself.

public enum ProductCategory
    {
        FOOD("label1"),
        BEVERAGE("label2"),
        DEFAULT("label3");

        private final String label;

        ProductCategory(String label)
        {
            this.label = label;
        }

        public String getLabel()
        {
            return label;
        }
    }

score 0 · Answer 4 · answered May 19 '17 at 18:22

public enum ProductCategory {
    FOOD("FOOD"), BEVERAGE("BEVERAGE"), DEFAULT("DEFAULT");

    private final String label;

    private ProductCategory(String label) {
        this.label = label;
    }

    public String getLabel() {
        return label;
    }
}

Constructor Enum error

4 Answers4