As its name indicates, ECMAScript 6 or ECMAScript 2015 is the sixth and latest version of the scripting language standard. The syntax rules of ECMAScript 6 make it easier for developers to write complex web application by taking advantage of new classes, modules, methods, keywords, and data types. At the same time, the version 6 of ECMAScript accelerates coding by providing a number of new shortcuts.
Overview of Important Features of ECMAScript 6/ ECMAScript 2015
While using ECMAScript 6, programmers can use classes developed based on a prototype-based object-oriented (OO) pattern. The developers can easily declare new classes in a declarative way by using the class keyword. They can even take advantage of the syntax rules of ECMAScript 6 to reuse code and create objects. The syntax rule further makes it easier for programmers to extend classes and instantiate new objects. The classes provided by ECMAScript 6 further supports prototype-based inheritance, instance and static methods, super calls, and constructors.
Modules make ECMAScript compete with several modern programming languages. While using the current version of the scripting language standard, programmers can take advantage of new syntax rules and a new module loader mechanism. The programmers can use the syntax rules to write modules which are compatible with latest web technologies and frameworks. At the same time, the module loader mechanism makes it easier for programmers to implement these modules.
While using ECMAScript 6, programmers can use a redesigned array object. The array object now supports both new static class methods as well as new array prototype methods. The current version of the scripting language standard further supports typed arrays. The programmers can use typed arrays, as byte-based data structures, to manipulate file format or implement network protocols.
ECMAScript supports a new primitive data type called symbols. The programmers can use symbols just like conventional primitive data types like number and string. But they can use symbols to create both unique constants and unique identifiers for object properties. Each time a programmer calls the symbol method, it will return a value of symbol data type. The value returned by the method will have static properties. But the static properties will be exposed to certain built-in objects.
In addition to supporting typed arrays, ECMAScript further provides a convenient option – destructuring – for extracting data from arrays and objects. The syntax rule enables programmers to assign a value to multiple variables simultaneously without writing additional code. Also, the developers can use destructuring to change variable names, simulate multiple return values, and assign default values to argument objects.
These function shorthand appears synthetically similar to the feature provided by modern programming languages like Java, C# and CoffeeScript. The programmers can define arrows by using the => syntax and without using the function keyword. An arrow supports both expression and syntax bodies. But the arrows, unlike functions, use the same lexical this as their surrounding code. The developers even have option to include arrows in functions. When an arrow is used inside a function, it uses the arguments used by the parent function.
The feature is similar to the string interpolation feature provided by Python or Perl. The programmers can take advantage of template literals to simplify string creation and interpolation. The template literals further enable developers to concatenate string in a different way. The programmers can further take advantage of template literals to embed different values into a template without any restriction.
Multi Line Strings
While using ECMAScript 6, programmers use a number of new keywords to keep the code clean and reusable. For instance, they can use the let keyword to declare local variables with the scope of a function, statement, or expression without writing additional code. Also, they have option to declare a variable using two keywords –var and let. Likewise, the constant keyword makes it easier for programmers to declare immutable values or constants. The programmer cannot assign new content to the constant. But they can change the value and properties of an object hold by the constant.
The new operators provided by ECMAScript 2015 also help programmers to write clean and reusable code. The developers can even use the new operators to perform common tasks without writing additional code. For instance, a programmer can use the spread operator (…) to represent a number of expected values. He can use the spread operator to insert elements of an array into another array or pass arguments to a function from an array.
ECMAScript 6 introduces a number of new built-in methods. The new methods make it easier for programmers to work with various objects – array, math, string, number, object, date, promise, proxy and reflect. The developers can further take advantage of these methods to manipulate various objects without writing additional code. However, several web browsers are yet to support the new methods provided by ECMAScript 2015.
On the whole, ECMAScript 6 comes with. The new language features enable to write custom and complex web applications rapidly. But various web browsers have been implementing the current version of ECMAScript gradually. Hence, the ECMAScript features supported by individual web browsers differ. The developers can easily transpile the code written in ECMAScript 6 to ECMAScript 5 through a command line or specific plug-ins. But they can always accelerate web application development by switching from ECMAScript 5 to ECMAScript 6.