Learn how to set the value of an enumeration type in Java

Value setting skills of enumeration types in Java

Overview of enumeration types

The enumeration type (enum) is a special type in Java Data type used to represent a fixed set of constants. Each value of an enumeration type is a constant and can only be an instance of that type. Enumeration types can be used to represent various concepts such as color, gender, status, etc.

Value setting tips for enumeration types

In Java, the value of an enumeration type can be set in the following ways:

• Explicitly Set value

public enum Color {
    RED(255, 0, 0),
    GREEN(0, 255, 0),
    BLUE(0, 0, 255);

    private int red;
    private int green;
    private int blue;

    private Color(int red, int green, int blue) {
        this.red = red;
        this.green = green;
        this.blue = blue;
    }

    public int getRed() {
        return red;
    }

    public int getGreen() {
        return green;
    }

    public int getBlue() {
        return blue;
    }
}

• Use constructor

public enum Color {
    RED,
    GREEN,
    BLUE;

    private Color() {
        // 构造函数中可以初始化枚举类型的值
    }
}

• Use static code block

public enum Color {
    RED,
    GREEN,
    BLUE;

    static {
        // 静态代码块中可以初始化枚举类型的值
    }
}

Code Example

The following is an article within 1500 words written according to the title, which contains specific code examples of value setting techniques for enumeration types in Java:

Value setting skills of enumeration types in Java

The enumeration type (enum) is a special data type in Java, used to represent a fixed set of constant. Each value of an enumeration type is a constant and can only be an instance of that type. Enumeration types can be used to represent various concepts such as color, gender, status, etc.

In Java, the value of an enumeration type can be set in the following ways:

• Explicitly setting the value

public enum Color {
    RED(255, 0, 0),
    GREEN(0, 255, 0),
    BLUE(0, 0, 255);

    private int red;
    private int green;
    private int blue;

    private Color(int red, int green, int blue) {
        this.red = red;
        this.green = green;
        this.blue = blue;
    }

    public int getRed() {
        return red;
    }

    public int getGreen() {
        return green;
    }

    public int getBlue() {
        return blue;
    }
}

This method is the most direct and the most commonly used method. In the declaration of an enumeration type, you can directly specify a value for each value of the enumeration type.

• Using constructors

public enum Color {
    RED,
    GREEN,
    BLUE;

    private Color() {
        // 构造函数中可以初始化枚举类型的值
    }
}

This approach is similar to explicitly setting the value, but it allows the enumeration to be set in the constructor Type value is initialized. This is useful for situations where you need to perform some calculations or operations on the values ​​of an enumeration type.

• Using static code blocks

public enum Color {
    RED,
    GREEN,
    BLUE;

    static {
        // 静态代码块中可以初始化枚举类型的值
    }
}

This approach is similar to using constructors, but it allows for enumeration in static code blocks Initialize with a value of type. This is useful in situations where the value of an enumeration type needs to be initialized before the enumeration type is loaded into memory.

Summary

The enumeration type is a very useful data type that can be used to represent a variety of concepts. In Java, the value of an enumeration type can be set in various ways. Depending on the situation, you can choose the most appropriate way to set the value of the enumeration type.

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