Gain insights into JavaScript fundamentals. Delve into variables, operators, functions, arrays, objects, and loops. Discover essential concepts to advance further in your coding journey with this beginner-friendly course.

This is an introduction to JavaScript for the complete beginner. It'll provide the fundamentals of the language. Topics include variables, operators, functions, arrays, objects, and loops. After this course, you should be ready to further your learning through advanced courses or other resources.

There is NO installation required for this course. Code can be viewed and run directly from the lessons.

This course has been created by Arnav Aggarwal, a full-stack engineer. Arnav has attended a coding boot camp and has taught at another one. He has extensive experience understanding how people learn to code. In under a month, Arnav's published articles on JavaScript concepts have received over 50,000 views and have been featured on Medium.com and code mentor.io due to their value.

After this course, check out the next one in the series.

Step Up Your JS: A Comprehensive Guide to Intermediate JavaScript

https://goo.gl/GjM8Mu

Introduction to JavaScript: First Steps

Loops are a new concept. They're very powerful. They're used to run a piece of code more than once so that we don't have to write the same code over and over. They have different use cases than functions.

Let's say we want to use `console.log()` ten times. We could write ten different statements, or we could use a loop.

# for-loops

For-loops follow a format which might seem daunting at first. Try to get through it.

We start a for-loop by writing the reserved keyword `for`, with parentheses after it.

    for()

Inside the loop, we need to put three pieces of information. This information will tell the loop how many times it should run and what it'll do after each run.

    for(/*first item*/; /*second item*/; /*third item*/)

We're trying to print something ten times, so we somehow need to tell our loop to run ten times. Let's see how to do that.

We'll discuss the first piece of information, then the last, then the second.

## Declare a Variable

Inside the parentheses, we first want to declare a variable. This will happen **once**, before the loop runs.

    for(let index = 0; /*second item*/; /*third item*/)
    
## Increase the Variable

At the *end* of the loop, we want to write something that will happen after every run of the loop. In our case, we want to increase `index` by one. So every time the loop runs, `index` gets increased by one.

    for(let index = 0; /*second item*/; index = index + 1)

## Condition

In the middle, we want to set a **condition**. The loop will run over and over until this condition becomes false. In our example, we want to run this loop ten times.

We have an `index` that starts at 0 and goes up by one every time the loop runs. We want to tell the loop to stop when `index` is equal to ten.

    for(let index = 0; index < 10; index = index + 1)

# Loop Body

We have our for-loop's backbone. This loop will run ten times and then stop. At the moment, it does nothing. We need to give this loop a *body*. We do this with the `{}` characters placed after the parentheses, just like in functions.

The code we write inside `{}` will run every time the loop runs.

    for(let index = 0; index < 10; index = index + 1) {
        // loop body
    }

Learn how to repeat a set of code as many times as you like, without using functions. For-loops are a fundamental part of every programming language. We'll see how to write them and how to use them with arrays.

Introduction

Variables

Operators & if-statements

Functions

Arrays

Objects

Loops

Conclusion

for-loops