Hello Jetto Net followers!

Welcome to our Java Object-Oriented Programming (OOP) series. In the previous post, we examined exception handling mechanisms to prevent program crashes in unexpected situations. In this article, we will explore "generics," a powerful feature in Java that enhances type safety and reduces code duplication.

What are Generics?

To start from the basics, in Java, every class structure we create is a subclass of the Object class. As a result, every object created is of type Object.

Due to this characteristic, we can use these objects in any data structure. While this does not cause errors during program compilation, it can lead to runtime errors if the program detects mismatched data types. Generics are a solution to this problem.

In short, Java Generics allow us to define classes, interfaces, or methods that can handle different reference data types, giving us control over which reference types we want them to support.

While the theoretical information might seem clear, seeing practical usage can help us better understand what generics are.

How to Use Generics?

To make a class, interface, or method generic, you need to specify a type parameter name in angle brackets (<>) after the class, interface, or method name. Type parameter names are typically single letters such as T, E, K, V.

public class Box<T> {
    private T content;
    public Box(T content) {
        this.content= content;
    }
    public T getContent() {
        return content;
    }
}

In the example above, we defined a generic class named Box. This class takes a type parameter named T, which represents the type of the data stored in the box.

Advantages of Generics

• Type Safety: Generics provide type safety at compile time. The compiler will throw an error if you try to work with incorrect types of data.
• Code Reusability: You don't have to rewrite the same code for different data types.
• Code Readability: Code written with generics is generally more readable.

Generics Usage Examples

Box<String> stringBox = new Box<>("Hello");
String message = stringBox.getContent();
Box<Integer> numBox = new Box<>(123);
int num = numBox.getContent();

In the example above, we created Box instances for String and Integer types.

Conclusion

Generics are an important feature in Java for type safety, code reusability, and readability. By using generics, we can write more secure, flexible, and maintainable code.

In our next post, we will continue to explore other important OOP concepts. Feel free to leave your questions or comments in the section below.

Happy Coding!