What is the final keyword in Java?

 In Java, the final keyword is used to indicate that something cannot be changed. The final keyword can be used with variables, methods, and classes.

When used with a variable, the final keyword indicates that the value of the variable cannot be changed. For example:

final int x = 5; x = 10; // error: cannot assign a new value to a final variable

When used with a method, the final keyword indicates that the method cannot be overridden by a subclass. For example:

public final void doSomething() { // method code goes here }

When used with a class, the final keyword indicates that the class cannot be subclassed. For example:

public final class MyClass { // class code goes here }

The final keyword is often used to ensure that certain values or objects cannot be changed, which can be useful for maintaining the integrity of an application. It can also be used to improve the performance of an application, because the Java runtime can optimize code that uses final variables and methods.

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