What is the purpose of the `native` keyword in Java?

• A. Indicates a method is implemented in platform-specific code
• B. Denotes a class belongs to a native library
• C. Specifies that a method can only be called from native code
• D. Designates a field as a native variable

Answer: (A)

The purpose of the native keyword in Java is to indicate that a method is implemented in platform-specific code, typically written in languages like C or C++. This allows Java to leverage existing libraries or system-level functionalities that require lower-level operations, which are not feasible or efficient to implement purely in Java.

When a method is marked as native, it signifies to the Java Virtual Machine (JVM) that the method's body will not be provided in the Java source code but rather in a separate implementation that is platform-dependent. This is commonly used for operations that are highly dependent on the underlying hardware or operating system, such as file system access, graphics operations, or system resource management.

Using the native keyword enables developers to extend Java's capabilities by integrating with native libraries, thus enhancing performance for certain tasks while maintaining Java's object-oriented principles in the rest of the application.