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目录

Java final Keyword

❮ Java Keywords

Example

Set a variable to final, to prevent it from being overridden/modified:

public class Main {
  final int x = 10;

  public static void main(String[] args) {
    Main myObj = new Main();
    myObj.x = 25; // will generate an error: cannot assign a value to a final variable
    System.out.println(myObj.x);
  }
}

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Definition and Usage

The final keyword is a non-access modifier used for classes, attributes and methods, which makes them non-changeable (impossible to inherit or override).

The final keyword is useful when you want a variable to always store the same value, like PI (3.14159...).

The final keyword is called a "modifier". You will learn more about these in the Java Modifiers Chapter.

Related Pages

Read more about attributes our Java Class Attributes Tutorial.

❮ Java Keywords