Introduction to recursion (Part 1 Theory)

#webdev #algorithms #javascript

Have you ever heard the term recursion function!?

if you're a developer - and you are of course - the answer would be definitely YES!

maybe this term makes you a little bit confused or maybe scared (as I'm at the first sight ) but please calm down it's really easy and very helpful.

We're going to divide this talk into two parts

Theory and Practical

Theory.

In theory, we need to answer 3 questions What, Why, and How.

WHAT?

ok, let's make it as simple as it indeed is.

Recursion is a "function calls itself".
Simply from the body of the function, we use the same function again over and over until reaches a certain result.

Yes, I've heard your question 😃
why would I make a function to call itself again and what the benefits of doing so?

Here we go to the next question

WHY?

recursion as you already guessed (maybe not) is similar to loops.

But when you work with a large number of data (Objects, Numbers, etc.)
loops became a cumbersome process to our program and maybe break it, especially when you make two loops in the same process or loop inside a loop this consumes a lot of resources and slows down the process.

But we as developers always trying to make our code clean, fast, and as efficient as possible, Right?

In this situation recursion becomes handy.

we use it when we got a big number of data we need to loop inside it but you care about the time and readability and efficiency of your code, ok?

let's jump to the last question of theory

HOW?

here's how it works, there are two parts recursion function must have to be a recursion

1-Different input:
we agreed that it's a "function calls itself" so it doesn't make sense to give the function the same input and expect to do a different thing so every time the function executed must have different input.

2-Base case:
because recursion function kinda loop,
and every loop must have a time where it stops and returns a value, or we're going to have an infinite loop.
the time we stop our recursion function is the base case of the function.
so when we say the base case of the recursion function it means the phase that stops and returns its result.

That's it for theory, I hope it was simple, and follow me for more ❤️