Hello;
My first programming language was Javascript. Learning JS without previos knowledge of programming theory ( paradigms, history and language background ) was a very painful process, full of pitfalls and roaming in the dark. As I can see, a lot of people had a same experience. From my point of view it is because in JS it is relatively easy to write applications that looks like a real applications - with the help of large number of libraries that provides usefull abstractions in the form of their "easy to learn" API. Canonical example is jQeury - with a minimal code you can have reference to DOM object, without knowing what is happening in the back:
//
var elem = $("div")
//
I am not saying that abstractions are evil, and that we should avoid them. It should be a nightmare to write code without them. After all with the help of abstractions, we are not writing assemby anymore, or in the case of jQuery, cool animations. I want to say that when learning language starting with libraries like jQuery can cause unnecessary confusion, which is hard to correct.
This is even more the case with JS, because of it‘s weird combinations of paradigms and idioms. For example, concept of
closure has become trademark of a language, that is very hard to pick without a knowledge about its context, root and origin. To proof, term
closure is one of the most searched programming term online, with blogs and even whole sites dedicated to it.
People are really having problem to digest closure. It is not a surprise, because it is one of the hardest programming concept that exist.
After years of struggling with JS I created my mental model about what is Javascript. Of course, it is not just a theory. I am a programmer and the whole point of this post is to better understand Javascript so I can express my self with code.
So lets examine some of the main bulding blocks of JS.
I‘ll start with
syntax, since it is very natural to start with when learning new language. Javascript belongs to so called "
curly-braces" family of languages, which is mostly influenced by
C.
Take a look at the following examples:
//
var i;
for ( i = 0; i < 5, i++){
console.log("hello");
};
int i;
for ( i = 0; i < 5, i++){
printf("%s\n","hello");
};
//
These two examples are identical, except one cosmetic difference. To write to output, Javascript uses
console.log method, which is specific to browser environment, and C uses
printf. Their syntatic similarity can also be seen through code formating that I use in this blog. Both loops are formatted using same pre tag (
<pre class = "brush:js">), which is JS specific. But the output is still well formed, except some minor color differences. Looking deeper in the languages syntax, there is very, very close relationship between them. I don't want to spend too much time dealing with that topic, since it is covered in more details on other places. To start with syntax comparison read a great Wiki articles:
Comparison of programming languages syntax and
List of programming languages by type.
The main takeaway from this is:
Take some to learn basis of C programming language. There are tons of great resources and tutorials online. You'll be surprised how much is Javascript influenced by C. In the beginning that influence can be seen as only syntatical, but with experience you'll see how much have you missed. I became enlightened after learning C.
And that is just a beginning. In the future posts I'll cover other important Javascript paradigms - first object and then functional.
Miro.
