JavaScript is controversial. There are enough developers who don’t like it, and there are even enough reasons for that. Yet, according to the Stack Overflow statistics, JS is the most popular technology among programming, scripting, and markup languages. Moreover, it has been holding the first place for the last nine years in a row!
However, there is a huge confusion when it comes to distinguishing JS, ECMA-262, ECMAScript, and its editions. Even writers from professional essay writing service can get tangled in the definitions despite the fact that they have a lot of experience in writing essays based on complicated plots and papers on Socrates’ philosophy. So, to keep it simple and clear as much as possible, let’s start with a bit of history.
What Are ECMAScript and ES 2015?
ECMA-262 is a standard for scripting languages developed by European Computer Manufacturers Association International. ECMAScript (ES) is sometimes called a language, but basically, it’s a specification of ECMA-262 – the set of rules a programming language should follow to be counted as an ES-compliant language.
ES 2015, just like its older and younger siblings, is the 6th edition of ES (that’s why it’s also called ES6 – 6th edition published in 2015).
What Is JavaScript?
JavaScript is a language that conforms to the rules of ECMAScript specifications. It is a scripting language that was first named Mocha, then – LiveScript, and then – JavaScript. The language has derived its name from Java, which was too complex to master, so JavaScript was created as a simpler substitute in less than two weeks!
Of course, it was rather trivial in comparison to what we have these days. Still, the foundation of the most popular programming language was built in 10 days, which is a significant achievement.
Its simplicity resulted in many flaws, of course. There are some bugs and illogical definitions that are too late to fix – most apps will suffer greatly if those issues are addressed.
Just imagine how many websites have been created in the last 26 years. If the bug gets fixed, for some time, we will lose most of our favorite and most needed apps and websites, including streaming services, essay writing services reviews platforms, and social media. So, let the bugs stay.
Anyway, the improvements JavaScript has seen since 1995 are much more considerable. When ES6 was released, it led to great changes in developers’ algorithms. That’s why ES6 is often compared with its predecessors. So, it would be correct to discuss what distinguishes ES6 and what was introduced before it.
5 Differences Between ES6 and Previous Specifications
The list of features introduced in ECMAScript 2015 is rather long, so it is actually impossible to cover all of them here. Yet, there are milestones that must be mentioned. Read on to find out about them.
Modules
JavaScript modules added in the 6th edition allow one to break up the long code into parts and import them from any file using default or named export. It helps when you need to divide specific functions or variables and is especially useful when you have a template for a reusable function but don’t need it in your main file. With the help of modules, the code becomes more organized and split logically.
Arrow Functions
Arrow functions offer much more concise syntax when compared to ordinary ones. It is not always evident until you see the difference between the mapping function in the two versions, for instance. The absence of a prototype, this, and arguments in arrow functions is also the thing to note to avoid waste of time when trying to find out why your code doesn’t work.
Transpiler
Basically, it is a translator of code that transforms ES6 JavaScript code into the ES5 one that has bulkier syntax. The most popular JS transpiler is called Babel. Any browser that exists out there has a JS interpreter, but those interpret ES5.
For a browser to understand the code written in line with the ES6 – which drastically differs from its older sibling – a transpiler is needed. It is not necessary if a developer follows only the ES5 standard when coding. However, the perks of ES6 leave no chances for ES5 to stay relevant these days.
Variables
In ECMAScript 2015, let and const had been introduced to substitute var since the latter was subject to hoisting and, hence, a variable could be used even though it hadn’t been declared yet. That could lead to ambiguity and messy code.
Although let and const pose some restrictions and add new rules regarding the initialization of variables declared via these keywords, the code becomes clearer and more organized. In addition, when you see the let keyword, you understand that the variable presupposes modifications in the future. When there is a const one, you know the opposite. With the var keyword, these two are indistinguishable.
Other Features
ECMAScript 2015 has also brought other perks that improved the language:
- classes;
- Symbol();
- methods for arrays (like keys(), findIndex(), and find());
- new Math methods (like cbrt() and sign();
- additional global methods (isNan() and isFinite());
- for/of statements to run loops;
- new String methods (like includes());
- block scope;
- promises.
To Sum Up
So, these are the main improvements ECMAScript 2015 has presented us with. Although new editions have been released later, ES6 is still considered a landmark one that revolutionized JS development.
