#es6features

1. let and const keywords : Users can define variables using the keyword "let," whereas they can define constants using the keyword "const." In the past, variables were declared by using the top-level keyword "var," which had function scope. It indicates that a variable may be utilized prior to declaration. But, the "let" variables and constants have block scope which is surrounded by curly-braces "{}" and cannot be used before declaration. let i = 10; console.log(i); //Output 10 const PI = 3.14; console.log(PI); //Output 3.14 2. Arrow Functions The Arrow Functions functionality is a part of ES6. By omitting the "function" and "return" keywords, it offers a more succinct syntax for creating function expressions. The fat arrow (=>) notation is used to define arrow functions. // Arrow function let sumOfTwoNumbers = (a, b) => a + b; console.log(sum(10, 20)); // Output 30 It is clear that the declaration of the arrow function does not contain the keywords "return" or "function." When there is precisely one parameter, we can omit the parenthesis; however, when there are zero or several parameters, we must always use them. However, we must enclose the function body in curly brackets ("{}") if it contains several expressions. In order to return the necessary value, we must also utilize the "return" statement. 3. Multi-line Strings Also available in ES6 are Multi-line Strings. Back-ticks(') are used to produce multi-line strings by users. The steps are as follows: let greeting = `Hello World, Greetings to all, Keep Learning and Practicing!` 4. Default Parameters In ES6, users can provide the default values directly in the function signature. However, with ES5, the OR operator was required. //ES6 let calculateArea = function(height = 100, width = 50) { // logic } //ES5 var calculateArea = function(height, width) { height = height || 50; width = width || 80; // logic } 5. Template Literals Very basic string templates and variable placeholders are also new features of ES6. The back-ticked string contains the syntax ${PARAMETER}, which is utilized to use the string template. let name = `My name is ${firstName} ${lastName}` 6. Destructuring Assignment One of the most used ES6 features is destructuring. An expression that makes it simple to separate off values from arrays or properties from objects into separate variables is the destructuring assignment. Destructuring assignment expressions come in two flavours: array destructuring and object destructuring. It can be applied in the ways listed below: //Array Destructuring let fruits = ; let = fruits; // Array destructuring assignment console.log(a, b); //Object Destructuring let person = {name: "Peter", age: 28}; let {name, age} = person; // Object destructuring assignment console.log(name, age); 7. Enhanced Object Literals Enhanced object literals are a feature of ES6 that make it simple to quickly build objects with properties inside curly braces. function getMobile(manufacturer, model, year) { return { manufacturer, model, year } } getMobile("Samsung", "Galaxy", "2020"); 8. Promises Promises are utilized for asynchronous execution in ES6. As shown here, we can combine promise and the arrow function. var asyncCall = new Promise((resolve, reject) => { // do something resolve(); }).then(()=> { console.log('DON!'); }) 9. Classes JavaScript has never before had classes. In ES6, classes are introduced. Classes in other object-oriented languages, such C++, Java, PHP, etc., resemble classes in ES6. But they don't operate in precisely the same manner. By employing the "extends" keyword to implement inheritance, ES6 classes make it easier to construct objects and reuse code effectively. In ES6, we can declare classes by preceding the class name with the new "class" keyword. class UserProfile { constructor(firstName, lastName) { this.firstName = firstName; this.lastName = lastName; } getName() { console.log(`The Full-Name is ${this.firstName} ${this.lastName}`); } } let obj = new UserProfile('John', 'Smith'); obj.getName(); // output: The Full-Name is John Smith 10. Modules Until recently, JavaScript lacked native support for modules. A brand-new function known as modules was added to ES6. Each module is represented by a distinct ".js" file. Variables, functions, classes, and other components can be imported or exported from or to different files and modules by using the "import" or "export" declaration in a module. export var num = 50; export function getName(fullName) { //data }; import {num, getName} from 'module'; console.log(num); // 50 Summary - This post introduced us to ECMAScript 2015, often known as ES6, which establishes the benchmark for JavaScript implementation. - The top 10 ES6 Features that make it so well-liked were also covered in this lesson. - Working with JavaScript is significantly facilitated by ES6's classes, modules, arrow functions, template literals, destructuring assignments, and many other features. Read the full article