Master the technique of setting variable values ​​using enumeration types in Java

An enumeration type is a special class type that allows you to create a fixed set of values ​​that can be used to represent a set of related options. In Java, you can use the enum keyword to create an enumeration type.

The enumeration type is declared as follows:

public enum MyEnum {
  OPTION1,
  OPTION2,
  OPTION3
}

In this example, we create an enumeration type named MyEnum which has three options:OPTION1, OPTION2 and OPTION3.

To use an enumeration type, you can use the . operator to access the options of the enumeration type. For example, the following code shows how to access the OPTION1 options of the MyEnum enumeration type:

MyEnum.OPTION1

You can also use enumeration types to set values. For example, the following code shows how to set the variable myEnum to the OPTION2 option:

MyEnum myEnum = MyEnum.OPTION2;

When you set a variable to an option of type enumeration, you actually is setting the variable to the constant value of the option. For example, when you set myEnum to the OPTION2 option, you are actually setting myEnum to the constant value of OPTION2, That is 2.

Enumeration types are great for representing a set of fixed values. For example, you can use enumeration types to represent a set of colors, a set of fruits, or a set of animals. Enumeration types can also be used to represent a set of statuses. For example, you can use an enumeration type to represent a set of order statuses or a set of user statuses.

Here are some tips for setting values ​​using enumeration types:

• Use the switch statement to perform different actions based on the options of the enumeration type. For example, the following code shows how to use the switch statement to perform different actions based on the options of the MyEnum enumeration type:

switch (myEnum) {
  case OPTION1:
    // Do something
    break;
  case OPTION2:
    // Do something else
    break;
  case OPTION3:
    // Do something else again
    break;
}

• Usingif statement to check whether an option of an enumeration type is equal to a certain value. For example, the following code shows how to use the if statement to check if myEnum is equal to the OPTION2 option:

if (myEnum == MyEnum.OPTION2) {
  // Do something
}

• Using for Loop through the options of an enum type. For example, the following code shows how to use a for loop to iterate through the options of the MyEnum enumeration type:

for (MyEnum option : MyEnum.values()) {
  // Do something with the option
}

The enumeration type is a very useful tool , which helps you represent a fixed set of values ​​in your code. Enumeration types can be used to improve code readability and maintainability.

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