Reconciliation: React provides a declarative API so that you don’t have to worry about exactly what changes on every update. This makes writing applications a lot easier, but it might not be obvious how this is implemented within React. …

Promise All polyfill 2. Array filter polyfill

function foo1() https://gist.github.com/priyanshuchauhan/18273ccffacd3e646b1b9983944caff2 https://gist.github.com/priyanshuchauhan/5e88257b40e0c5078a9db16302f31bed console.log(test) typeof bar === “object” 3. First-class Function: a. Assign a function to a variable const foo = function() { console.log(“foobar”); } // Invoke it using the variable foo(); b. Pass a function as an Argument function sayHello() { return “Hello, “; } function greeting(helloMessage, name)…

Referring to Dostoevsky’s quote: Prototype and “this” are source code of unhappiness in JS since ES6. this, Bind, call, apply (Call Site): Below code snippet covers it all (plus bit of ES6 setPrototypeOf) setPrototypeOf ?

1. JS Event delegation JS event listeners fire not only on a single DOM element but on all its descendants. 2. Event bubbling Inverse of delegation. Also known as propogation, vents on an element will “bubble up” and also fire on all parents. 3. Difference between “target” and “currentTarget” The…

var UserClass = (function() { //private var foo = 'testtt'; //private Method function sum(a, b) { return a + b; } // constructor function UserClass(name, age) { //public variables this.username = name; this.age = age; foo = 'hello' } // public method UserClass.prototype.getName = function() { return this.username; } return UserClass; })(); var userInstance = new UserClass("kamlesh", 30); userInstance.getName(); userInstance.age; userInstance.foo; //error since private

Class without ES6: new keyword does 5 things: a. It creates a new object. The type of this object is simply object. b. It sets this new object’s internal, inaccessible, [[prototype]] (i.e. proto) property to be the constructor function’s external, accessible, prototype object (every function object automatically has a prototype property). c. It makes the this…

Roadmap to becoming a web developer Roadmap to becoming a web developer in 2018 Below you find a set of charts demonstrating the paths that you can take and the technologies that you would want to adopt in order to become a frontend, backend or a devops. …

Table of Contents Introduction Variables Functions Objects and Data Structures Classes SOLID Testing Concurrency Error Handling Formatting Comments Translation Introduction Software engineering principles, from Robert C. Martin’s book Clean Code, adapted for JavaScript. This is not a style guide. It’s a guide to producing readable, reusable, and refactorable software in JavaScript. Not every principle…