Generic classes in TypeScript play a pivotal role in enhancing flexibility and reusability in code design. They empower developers to create classes that can work with a diverse range of data types, providing a dynamic and adaptable foundation for building robust applications.

Understanding Generic Classes: Unlike regular classes that work with specific data types, generic classes allow developers to design classes that can be instantiated with a variety of types. This flexibility is achieved through the use of type parameters, which act as placeholders for the actual types that will be provided during class instantiation.

Syntax of Generic Classes: The syntax for declaring a generic class involves specifying one or more type parameters within angle brackets (< >) when defining the class. These type parameters are then used throughout the class definition, allowing for a generic approach.

class MyGenericClass<Type> {
  private data: Type;

  constructor(initialValue: Type) {
    this.data = initialValue;
  }

  getData(): Type {
    return this.data;
  }
}

Benefits of Generic Classes:

1. Code Reusability: Generic classes enable the creation of versatile components that can be reused with different data types, reducing redundancy in code.

2. Flexibility in Data Handling: With generic classes, developers can build components that maintain type specificity while accommodating a wide range of data types.

3. Type Safety: The use of generics ensures that the data types expected by the class are enforced during development, catching potential errors at compile-time rather than runtime.

Example: Generic Class for a Shopping Cart

interface Quiz {
  name: string;
  type: string;
}

interface Course {
  name: string;
  tutor: string;
  subject: string;
}

class Sell<T> {
  public cart: T[] = [];

  addToCart(product: T): void {
    this.cart.push(product);
  }
}

// Create an instance for Quizzes
const quizStore = new Sell<Quiz>();
const quizItem: Quiz = { name: "JavaScript Quiz", type: "Multiple Choice" };
quizStore.addToCart(quizItem);

// Create an instance for Courses
const courseStore = new Sell<Course>();
const courseItem: Course = { name: "Web Development", tutor: "John Doe", subject: "HTML/CSS" };
courseStore.addToCart(courseItem);

console.log(quizStore.cart);   // Outputs: [ { name: 'JavaScript Quiz', type: 'Multiple Choice' } ]
console.log(courseStore.cart); // Outputs: [ { name: 'Web Development', tutor: 'John Doe', subject: 'HTML/CSS' } ]

Explanation:

• The Sell class is defined with a generic type parameter T.

• It has a cart property that is an array of items of type T.

• The addToCart method allows adding items of type T to the cart.

• We create instances of Sell for different types (Quiz and Course) by specifying the type argument when creating instances (new Sell<Quiz>() and new Sell<Course>()).

• We add items to the respective carts and print their contents.

Generic classes provide a powerful mechanism for creating reusable and flexible components that can work with a variety of data types.

Stay tuned for more TypeScript insights and practical tips!