Lesson: Enum

package org.enums;

public enum Operation {
    SUM('+'),
    SUBTRACT('-'),
    MULTIPLY('*'),
    DIVIDE('/');

    private char c;

    Operation(char c) {
        this.c = c;
    }

    public char getC() {
        return c;
    }

} 

package org.enums;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        char c = in.nextLine().charAt(0);

        Operation operation = Operation.SUM;
        double calculate = calculate(5, 3, operation);
        System.out.println(calculate);
        System.out.println(operation.getC());

        if(c == operation.getC()) {
            System.out.println("Equal");
        }
    }

    public static double calculate(double a, double b, Operation operation) { // burada restrict edirik
        if (operation == Operation.SUM) {
            return a + b;
        } else if (operation == Operation.SUBTRACT) {
            return a - b;
        } else if (operation == Operation.DIVIDE) {
            return a / b;
        } else
            return a * b;
    }
}

 

-- Eslinde enum yaradanda arxa planda ne baw verir:

package az.etibarli.test5;

public class Operation2 {

    private static final Operation2 SUM = new Operation2('+');
    private static final Operation2 SUBTRACT = new Operation2('-');
    private static final Operation2 MULTIPLY = new Operation2('*');
    private static final Operation2 DIVIDE = new Operation2('/');

    private char c;

    public Operation2(char c) {
        this.c = c;
    }

    public char getC() {
        return c;
    }
}

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package org.enums;

public enum Operation {
    SUM('+'),
    SUBTRACT('-'),
    MULTIPLY('*'),
    DIVIDE('/'),
    UNKNOWN;

    private char c;

    Operation() {
    }

    Operation(char c) {
        this.c = c;
    }

    public char getC() {
        return c;
    }

    public static Operation getOperation(char c) {
        if (c == '+') {
            return SUM;
        } else if (c == '-') {
            return SUBTRACT;
        } else if (c == '*') {
            return MULTIPLY;
        } else if (c == '/') {
            return DIVIDE;
        }
        return UNKNOWN;
    }
}

package org.enums;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        char c = in.nextLine().charAt(0);
        Operation operation = Operation.getOperation(c);
        System.out.println(calculate(5, 8, operation));
    }

    public static double calculate(double a, double b, Operation operation) { // burada restrict edirik
        if (operation == Operation.SUM) {
            return a + b;
        } else if (operation == Operation.SUBTRACT) {
            return a - b;
        } else if (operation == Operation.DIVIDE) {
            return a / b;
        } else
            return a * b;
    }
}

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package org.enums;

public enum Digits {

    ZERO(0),
    ONE(1),
    TWO(2),
    THREE(3),
    FOUR(4),
    FIVE(5),
    SIX(6),
    SEVEN(7),
    EIGHT(8),
    NINE(9),
    UNKNOWN();

    private int number;

    Digits() {
    }

    Digits(int number) {
        this.number = number;
    }

    public int getNumber() {
        return number;
    }

    public static Digits getDigit(int number) {
        if(number < 0 || number > 9){
            return UNKNOWN;
        }
        return Digits.values()[number];
    }
}

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package org.enums;

public enum Size {
    SMALL("S", 1),
    MEDIUM("M", 2),
    LARGE("L", 3),
    EXTRA_LARGE("XL", 4);

    private String abbreviation;
    private int no;

    private static String description;
    private static int count;

    static {
        System.out.println("in static initialization block");
        description = "These are sizes.";
    }

    {
        // count++; // can't do this
        System.out.println("in object initializer block");
    }

    Size(String abbreviation, int no) {
        this.abbreviation = abbreviation;
        this.no = no;
        // count++; // can't do this
    }

    public String getAbbreviation() {
        return abbreviation;
    }

    public int getNo() {
        return no;
    }
}