Why Generic function declaration in Kotlin? - Purpose & Use Cases

The Big Idea

What if you could write one function that magically works for any type of data?

The Scenario

Imagine you want to write a function that works with different types of data, like numbers, text, or even custom objects. Without a generic function, you'd have to write the same function many times for each type.

The Problem

Writing separate functions for each type is slow and boring. It also makes your code longer and harder to fix if you find a mistake. Plus, you might forget to update one version, causing bugs.

The Solution

Generic function declaration lets you write one function that works with any type. It saves time, keeps your code clean, and reduces mistakes by reusing the same logic for all types.

Before vs After

✗ Before

fun printInt(value: Int) { println(value) }
fun printString(value: String) { println(value) }

✓ After

fun <T> printValue(value: T) { println(value) }

What It Enables

It enables you to write flexible and reusable functions that adapt to any data type effortlessly.

Real Life Example

Think of a function that sorts a list of any kind of items, like numbers or names, without rewriting the sorting logic for each type.

Key Takeaways

Writing separate functions for each type is inefficient.

Generic functions let you write one function for many types.

This makes your code cleaner, shorter, and easier to maintain.