ECMAScript 6 review, explanation, comparsion with ECMAScript 5

HI. If you are here. It seems you’ve heard about ECMAScript 6, and want to know more.

If we’ll check Wikipedia, it says that ECMAScript is a ‘trademarked scripting-language specification’. It means that ES - it’s a specification or in another words standards of scripting languages, such as JavaScript, ActionScript, Jscript. ECMAScript it is actually core of that languages, standards they are based at.

ECMAScript 6

Known as ES6 or ECMAScript 2015 was finalized in June 2015. There were added renewed syntax to create complexed javascript applications with classes, modules etc.

ES6 code example

Arrow functions:

    odds  = evens.map(v => v + 1)
    pairs = evens.map(v => ({ even: v, odd: v + 1 }))
    nums  = evens.map((v, i) => v + i)

Classes:

    class Rectangle extends Shape {
        constructor (id, x, y, width, height) {
            super(id, x, y)
            this.width  = width
            this.height = height
         }
    }
    class Circle extends Shape {
        constructor (id, x, y, radius) {
            super(id, x, y)
            this.radius = radius
        }
    }

ES6 vs ES5

Here is very useful website by Ralf S. Engelschall, which simply shows new features of ES6 by comparing code with ES5: es6-features.org

Browser support

Google Chrome and Mozilla Firefox support almost whole functionality of ES6, Microsoft Edge also is not doing bad. Other browsers have not full support. And as you might guess, Internet Explorer does not support Javascript in ECMAScript6. Here is full browser support table: kangax.github.io/compat-table/es6/

But don’t upset! You can write production ready applications using ES6. You just need to compile it throught Babel which transforms your code to Javascript in ES5.

Conclusion

No doubt, ECMAScript 6 is sexy! If you haven’t tried coding in ECMAScript 6 just open Chrome dev tools and try it out. You will definitely love it! Start with simple arrow functions:

    a = x => x*2;
    a(10);

Good luck ;)