Typescript Generics Development Tutorials, Guides & Insights

TypeScript is a powerful language that extends JavaScript by adding static types, allowing developers to catch errors early and write more robust code. While TypeScript's basic type features are relatively straightforward, its advanced features like type manipulation and generics allow for even more expressive and efficient code. In this tutorial, we'll explore how to optimize your TypeScript code using advanced type manipulation and generics, making your applications more maintainable and less error-prone.

To get the most out of this tutorial, you should have a basic understanding of TypeScript, including how to define types, interfaces, and basic generics. If you're new to these concepts, consider reviewing them before diving into this tutorial.

function getFirstElement<T>(arr: T[]): T {
  return arr[0];
}

const firstNumber = getFirstElement([1, 2, 3]); // number
const firstString = getFirstElement(['a', 'b', 'c']); // string

This function works with any array type and returns the first element, maintaining the type of the elements.

function Log(target: any, propertyKey: string, descriptor: PropertyDescriptor) {
  const originalMethod = descriptor.value;
  descriptor.value = function (...args: any[]) {
    console.log(`Calling ${propertyKey} with`, args);
    return originalMethod.apply(this, args);
  };
}

class Calculator {
  @Log
  add(a: number, b: number): number {
    return a + b;
  }
}

const calculator = new Calculator();
calculator.add(5, 3); // Logs: Calling add with [5, 3]

TypeScript is commonly used with React to ensure type safety in components: