Instruction

This lesson serves as a thorough guide to crafting flexible and maintainable code. Throughout it, you’ll learn:

• How to create generic classes, allowing one class to handle different data types smoothly.
• How to use generic methods to enhance your functions seamlessly with various data sets.
• About generic constraints, which help set structured rules for your code.

Time to get started!

In Kotlin, a generic class is a class that can be parameterized with types, allowing it to work with different data types while maintaining type safety. It’s defined with one or more type parameters inside angle brackets after the class name. Instances of the generic class can then be created with specific types, providing flexibility and reusability.

For example, class FruitBox<T>(value: T) is a generic class that can hold values of any type T. This enables code to be more concise and adaptable by promoting the reuse of the same class logic for various data types.

On the other hand, the Generic method is a function that can work with different data types by using type parameters. It’s declared with angle brackets and type parameters before the return type. The type parameters allow the method to be flexible and provide type safety.

To create a generic class in Kotlin, you use the class keyword followed by angle brackets to declare type parameters. These parameters represent placeholders for actual types specified when creating class instances. You can use the type parameters inside the class body wherever the type is relevant. When you instantiate the generic class, you provide concrete types for the parameters.

For instance, in the example of a FruitBox class, the type parameter T is used to hold values, and instances can be created with specific types like Int or String. This flexibility allows for code reuse and adaptability across various data types, promoting a more concise and generic approach to class design in Kotlin.

Generic constraints, also known as type constraints, let you restrict the types that can be used with a generic class or method. Constraints are specified using the where keyword and conditions on the type parameters. This ensures that the generic class or method operates only on types that satisfy certain criteria, such as implementing specific interfaces or having certain properties. Constraints enhance type safety and enable more precise control over the allowed types in generic constructs.

Now that you understand the generic class better, watch the video demo explaining everything.