Why Generic arrow functions in Typescript? - Purpose & Use Cases

The Big Idea

What if one simple function could work perfectly with any kind of data you throw at it?

The Scenario

Imagine you need to write many small functions that do similar things but work with different types of data, like numbers, strings, or objects. Writing each function separately means a lot of repeated code.

The Problem

Writing separate functions for each data type is slow and boring. It's easy to make mistakes when copying and changing code. Also, if you want to change the logic, you must update many places, which wastes time and causes bugs.

The Solution

Generic arrow functions let you write one flexible function that works with any data type. You write the logic once, and TypeScript helps you keep it safe and correct for all types. This saves time and reduces errors.

Before vs After

✗ Before

function identityNumber(x: number): number { return x; }
function identityString(x: string): string { return x; }

✓ After

const identity = <T>(x: T): T => x;

What It Enables

It enables writing reusable, type-safe functions that adapt to any data type effortlessly.

Real Life Example

Think of a function that returns the first item of any list, whether it's a list of names, ages, or products. Generic arrow functions let you write this once and use it everywhere.

Key Takeaways

Writing separate functions for each type is repetitive and error-prone.

Generic arrow functions let you write one flexible function for all types.

This saves time, reduces bugs, and keeps your code clean and safe.