Is it possible to assign numeric value to an enum in Java?

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傲寒
傲寒 2020-12-07 17:29

Is anything like this possible in Java? Can one assign custom numeric values to enum elements in Java?

public enum EXIT_CODE {
    A=104, B=203;
}

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  •  既然无缘
    2020-12-07 17:42

    Yes, and then some, example from documentation:

    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);
    
        // in kilograms
        private final double mass;
        // in meters
        private final double radius;
        Planet(double mass, double radius) {
            this.mass = mass;
            this.radius = radius;
        }
        private double mass() { return mass; }
        private double radius() { return radius; }
    
        // universal gravitational 
        // constant  (m3 kg-1 s-2)
        public static final double G = 6.67300E-11;
    
        double surfaceGravity() {
            return G * mass / (radius * radius);
        }
        double surfaceWeight(double otherMass) {
            return otherMass * surfaceGravity();
        }
        public static void main(String[] args) {
            if (args.length != 1) {
                System.err.println("Usage: java Planet ");
                System.exit(-1);
            }
            double earthWeight = Double.parseDouble(args[0]);
            double mass = earthWeight/EARTH.surfaceGravity();
            for (Planet p : Planet.values())
               System.out.printf("Your weight on %s is %f%n",
                                 p, p.surfaceWeight(mass));
        }
    }
    

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