JAVA constructor not accepting enum values

Question

Tried this code to learn functional Java but my Person constructor not accepting enum values, giving a compilation error and is not taking named parameters gving syntax error. Kindly poit to the error I am making.

 package imperative;

import java.util.List;

public class Main {
    private static String name;
    public static void main(String[] args) {
        List<Person> people = List.of(
                    new Person(name:"John",MALE),
                    new Person(name:"Alexa",FEMALE),
                    new Person(name:"Sam",MALE),
                    new Person(name:"Maria",FEMALE),
                    new Person(name:"Drake",MALE)
                );
    }
    class Person{
        private final String name;
        private final Gender gender;
        public Person(String name, Gender gender) {
            super();
            this.name = name;
            this.gender = gender;
        }
        @Override
        public String toString() {
            return "Person [name=" + name + ", gender=" + gender + "]";
        }
    }
        enum Gender{
            MALE,FEMALE
        }
    
}

Does this answer your question? [How to pass an enum value to a constructor](https://stackoverflow.com/questions/20069410/how-to-pass-an-enum-value-to-a-constructor) — Dren, Feb 28 '21 at 14:09

score 2 · Answer 1 · answered Feb 28 '21 at 14:12

2

First of all, make your class Person static, as you're using it in a static method:

static class Person {

Then use qualified enum values like Gender.MALE or Gender.FEMALE. Finally invoke the constructor as follows:

public static void main(String[] args) {
    List<Person> people = List.of(
            new Person("John", Gender.MALE),
            new Person("Alexa", Gender.FEMALE),
            new Person("Sam", Gender.MALE),
            new Person("Maria", Gender.FEMALE),
            new Person("Drake", Gender.MALE)
    );
}

answered Feb 28 '21 at 14:12

ETO

6,970
1
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enum issue solved still facing ":" invalid operator error..Can you help? – Samrat Das Feb 28 '21 at 14:26
@SamratDas Did you try to run my code? I removed the `name: ` parts as well. – ETO Feb 28 '21 at 14:31

Marco Altieri · Accepted Answer · 2021-02-28T14:43:57.253

2

The following code compiles:

package imperative;

import java.util.List;

public class Main {
    private static String name;
    public static void main(String[] args) {
        List<Person> people = List.of(
                    new Person("John",Gender.MALE),
                    new Person("Alexa",Gender.FEMALE),
                    new Person("Sam",Gender.MALE),
                    new Person("Maria",Gender.FEMALE),
                    new Person("Drake",Gender.MALE)
                );
    }
    static class Person{
        private final String name;
        private final Gender gender;
        public Person(String name, Gender gender) {
            super();
            this.name = name;
            this.gender = gender;
        }
        @Override
        public String toString() {
            return "Person [name=" + name + ", gender=" + gender + "]";
        }
    }
        enum Gender{
            MALE,FEMALE
        }
    
}

It was necessary to fully qualify MALE and FEMALE and pass the name as a string: no need to use the syntax

name: "John"

edited Feb 28 '21 at 14:43

answered Feb 28 '21 at 14:25

Marco Altieri

3,726
2
33
47

yeah but still wondering why "name:" is not working – Samrat Das Feb 28 '21 at 14:27
1

Your constructor is accepting as input a String and an instance of Gender. The syntax name: "John" is not valid in Java. – Marco Altieri Feb 28 '21 at 14:28
This won't compile. The `Person` class should be declared **static**. – ETO Feb 28 '21 at 14:32
@Marco Actually found this syntax in a video tutorial – Samrat Das Feb 28 '21 at 14:35
@SamratDas, interesting. It is possible that is a new syntax and I am not aware of. Let me see. – Marco Altieri Feb 28 '21 at 14:40
How can a non-static instance of Person be instantiated without any instance of Main? – Tenfour04 Feb 28 '21 at 14:42
Fixed it :). You are right. – Marco Altieri Feb 28 '21 at 14:44
@SamratDas can you link the video? Java doesn’t support named parameters at the call site. – Tenfour04 Feb 28 '21 at 14:47

JAVA constructor not accepting enum values

2 Answers2