JavaScript is an incredibly popular language that remains poorly understood by many of the people who use it. This is largely because it can easily be picked up in the context of a specific project without learning it from the ground up.
Personally, I don't think this is a bad thing. In fact, one of my favorite things about JavaScript as a language is the fact that it's forgiving, it's accessible, and -- at least in my experience -- JavaScript programmers come from a tremendously diverse set of backgrounds. In my mind, JavaScript is the 'great-equalizer' in the computer programming world, and it is my hope that this will help to solve the diversity problem that has plagued the software development world for years.
On the other hand, JavaScript stands in stark contrast to languages like Java, C++ and Python which are widely taught to beginning programmers in Computer Science curricula around the United States. Because of the fact that there proliferation of ground-up training programs for these languages, there is a base-line of knowledge that can be expected. This is absolutely not true of JavaScript.
And while there are plenty of resources for the new JavaScript programmer, the vast majority of them are contextualized to a specific use-case (DOM manipulation or Node.js for example). Adding to the confusion is the fact that many of creators of these materials invent their own 'best-practices,' abstractions, and non-standard APIs.
This set of material is designed to fill the gap. It takes much of the material taught in a first-semester programming class in a Computer Science curriculum and recasts it in the JavaScript world. Due to the functional, class-less and weakly typed nature of JavaScript, this requires some re-thinking and reorganization of some of these fundamental concepts. But, at the end of the day, this material represents my view of the base-line knowledge that every JavaScript programmer should have.
In that spirit, it focuses exclusively on the language, and not on any specific application. While we'll have the opportunity to use and manipulate HTML strings in our examples, we won't demonstrate any DOM APIs, or Node.js, or any other special libraries.
There are two audiences for this set of material. The primary audience is people who have some experience with computers, but have never actually written a computer program. The ideal member of this audience is comfortable with using a keyboard and mouse, navigating files on their computer, and using a web-browser. They also are comfortable with basic arithmetic (the order of operations, for example).
The second audience is JavaScript programmers who may have learned programming in the context of client-side scripting or on-the-job, but are intersted in a deeper understanding of JavaScript as as a language, perhaps preparing themselves for further study. This audience will likely breeze through some of the sections, but may find some of the best-practice suggestions, along with some of the material in later sections to be unfamiliar.
The material includes variable declarations and definitions, function
definitions, types, conditional statements, loops (with a focus on for-loops),
arrays, built-in array methods, and objects (not OOP -- objects as maps).
We'll leave JS OOP as an intermediate topic. Also, we will not cover any specific use-case for JavaScript. That means we won't talk about the DOM and client-side web development, Node.js and server-side development, nor will we discuss robots.
On occasion, we'll use HTML and Twitter data in our examples, but for the most part we won't be interacting with any APIs external to JavaScript.
You'll get the most out of this material if you follow along and type in all the examples with me. I've created a file in each directory called "notes" that you can use to type in code and run the code in your browser.
You can tweet at me (@semmypurewal) or e-mail me ([email protected]) with questions. You can also use the "Issues" feature of our Github repository if you think your question might be relevant to others.
In our Github repository there is also a branch called solutions. You can access it by clicking the branch drop-down menu above the code browser on Github. This branch contains solutions to all of the tested practice problems.
Download the examples from our Github repository. The github repository can be found here. On the right-hand side, you'll see a button that says "Download ZIP." Download that file and unzip it somewhere on your hard-drive that you can easily access (your Desktop, pearhaps?).
You can also download the .zip file through this direct link.
We'll work with the Chrome browser. You can download it for free here.
Open up the browser and type about:blank into the address bar.
You can access the JavaScript console by going to
View->Developer->JavaScript Console
in the application menu.
Type console.log("hello world"); at the prompt. You'll see "hello world"
printed out.
You'll need a text editor that will help you interact with the text files. I recommend using Sublime Text 3. You can get a free evaluation copy of it to use here. Download it and install it.
Open up notes.js in your text editor and notes.html in your browser. If you
open up the JavaScript console, you should see hello world!. That's coming
from the notes.js file.
You can edit the notes.js file and reload the browser to see your updated code
run.