How To Slow Down A For-Loop in JavaScript

How To Slow Down A For-Loop in JavaScript

Yes, it’s possible due to a simple trick. For loops are indispensable. They help us to program sequences.

For loops are indispensable. They help us to program sequences.

But there is one problem with them — the for loop runs through as fast as possible. If we iterate through an array, this is, of course, desirable.

But if we do, e.g., requests in the loop, this can lead to problems.

It would be nice if each loop's execution takes a fixed time interval — for example, one pass per second.

I will show you how to do this — here is how to time a for-loop.

First — how it does not work

If you’re looking for a direct solution to your problem, feel free to skip this part. If you want to learn something about JS, then stay for a moment.

I want to explain why common solutions don’t work.

Thanks to setTimeout,d we can specify that a certain code should be executed only after x-time. This sounds like the solution to our problem. Just put the timeout in the for-loop, and the loop is less fast:

for (let i = 0; i < 100; i++) {
      setTimeout(() => {
      }, 1000)

When we run the code with setTimeout, the following happens:

nothing happens for 1 second; then all the logs come up in a flash.

Not really what we had hoped for.

The reason for this is a small error in thinking. It seems like the timeout doesn’t apply to every element — yes, it does.

But we forget how JavaScript executes code. The loop creates all timeouts immediately, not sequentially. Of course, this is very fast — so all timeouts have almost the same start time.

As soon as the time is up, the logs are made — all at once.

javascript programming nodejs

Bootstrap 5 Complete Course with Examples

Bootstrap 5 Tutorial - Bootstrap 5 Crash Course for Beginners

Nest.JS Tutorial for Beginners

Hello Vue 3: A First Look at Vue 3 and the Composition API

Building a simple Applications with Vue 3

Deno Crash Course: Explore Deno and Create a full REST API with Deno

How to Build a Real-time Chat App with Deno and WebSockets

Convert HTML to Markdown Online

HTML entity encoder decoder Online

Decoding Nodejs

The main goal of this blog is to explain the “Architecture of Nodejs” and to know how the Nodejs works behind the scenes. Generally, most of the server-side languages, like PHP, ASP.NET, Ruby, and including Nodejs follows multi-threaded architecture. That means for each client-side request initiates a new thread or even a new process.

Hire NodeJs Developer

Looking to build dynamic, extensively featured, and full-fledged web applications? **[Hire NodeJs Developer]( "Hire NodeJs Developer")** to create a real-time, faster, and scalable...

Learning JavaScript: Development Environments for JavaScript Programming

One of the nice things about learning JavaScript these days is that there is a plethora of choices for writing and running JavaScript code. In this article, I’m going to describe a few of these environments and show you the environment I’ll be using in this series of articles.

Learning JavaScript: Data Types and Variables

To paraphrase the title of an old computer science textbook, “Algorithms + Data = Programs.” The first step in learning a programming language such as JavaScript is to learn what types of data the language can work with. The second step is to learn how to store that data in variables. In this article I’ll discuss the different types of data you can work with in a JavaScript program and how to create and use variables to store and manipulate that data.

[ Professor JavaScript ]: Introduction

Professor JavaScript is a JavaScript online learning courses YouTube Channel. Students can learn how to develop codes with JavaScript from basic to advanced levels through the online courses in this YouTube channel.