#define in Java

If you’ve worked with C or C++, you’re probably familiar with #define, which is used to define constants or macros before compilation. But when you switch to Java, you’ll quickly notice that it doesn’t support the #define preprocessor directive. So the natural question is — how do you define constants or similar functionality in Java?

 Java’s Way of Doing It:

Instead of #define, Java uses other approaches to achieve the same results in a cleaner and more structured way.

 Use final with static:

To define constants in Java, you typically use:

  public static final int MAX_SIZE = 100;

• static means the constant belongs to the class, not instances of the class.
  
• final means the value cannot be changed after it’s set.
  
• Constants are usually written in all uppercase letters by convention.
  

 Example:

public class AppConstants {

    public static final String APP_NAME = "MyApp";

    public static final int TIMEOUT = 5000;

}

You can access them like:

  System.out.println(AppConstants.APP_NAME);

 Why Java Avoids #define:

Java was designed to be simple and readable, so it avoids preprocessor directives altogether. This helps reduce bugs and makes the code easier to maintain.

So while Java doesn't support #define directly, using static final variables is the standard and much safer alternative. It keeps your code organized, type-safe, and easy to refactor.