Mastering TypeScript Generics

Generics are a powerful feature in TypeScript that allow you to write flexible, reusable code while maintaining type safety. They act as placeholders for types that can be specified when a function or class is used.

Why use Generics?

Without generics, we often resort to any, which defeats the purpose of TypeScript.

// Without generics
function identity(arg: any): any {
  return arg;
}
 
// With generics
function identity<T>(arg: T): T {
  return arg;
}

In the second example, TypeScript captures the type of the argument and ensures the return type matches it.

Common Use Cases

1. Reusable Components: Building UI libraries that can handle any data type.
2. Utility Functions: Functions like map, filter, or API wrappers.
3. Data Structures: Creating generic Lists, Stacks, or Queues.

Understanding generics elevates your TypeScript skills from basic to advanced.