Free Online Tutorial For Programmers, Contains a Solution For Question in Programming. Quizzes and Practice / Company / Test interview Questions.
Are trying for a job in Javascript?
This is the perfect platform for you to prepare yourself for the interview because here you will get to study in detail that related to Javascript interview questions and answers for experienced, along with javascript tutorial. Once you finish reading javascript in detail you can take a quiz on the same website.
After taking the test you will come to know how best you are prepared. In case you get any of the answers incorrect you can just go back and read again. The test will have a Set of Object-oriented javascript interview questions and answers that are frequently asked in interviews.
Nullish coalescing operator The nullish coalescing operator(??) is a logical operator Returns its right-hand side operand when its left-hand side operand is null or undefined, and otherwise returns its left-hand side operand const name = null ?? 'John'; console.log(name); // John
How to avoid common errors in Javascript Introduction Now we have learned about error types and how to debug the errors Now there is a standard way of coding which can help in avoiding most of the common error types like ReferenceError and TypeError Use try-catch block To avoid errors…
How to debug errors in the javascript Introduction Now we have learned what are error types in the javascript and where we can find the error details Now it’s a time to learn how to debug the errors When any error occurs in the application, the error details can be…
Module in JavaScript Introduction Is a reusable piece of code Modules are building blocks of any complicated Software Module encapsulates implementation details Modules can be imported Modules can be exported Modules are imported synchronously Example Create file index.html Create a file script.js Create a file auth.js //index.html <html> <body> <script…
Concurrency model & event loop in Javascript Key points The event loop is responsible for executing the code collecting and processing events and executing queued sub-tasks JS Runtime Concepts The following sections explain a theoretical model Modern JavaScript engines implement and heavily optimize the described semantics Call Stack: Where the…
Classes in Javascript Introduction Classes are a template for creating objects They encapsulate data with code to work on that data The class syntax has two components: class expressions and class declarations Key points Class declarations are not hoisted Trying to access a class before declaring, gives a ReferenceError Class…
Object in Javascript Introduction JavaScript has an object entity with a combination of properties An object has the key-value pair Every element has a name which is called key Objects help to group together different variable that belongs to the same person or entity In object, the order doesn’t matter…
Events in Javascript Introduction Events are actions that happen in the system The system tells you about so you can respond to them in some way if desired For example, if the user selects a button on a webpage, you might want to respond to that action by displaying an…
new operator and function constructor in Javascript Constructor function The constructor function can be created with a new keyword When a new operator is used to create a function the following things happen How it works The new empty object is created The function is called and this keyword is…
IIFE Immediately Invoked Function Expression Introduction Is a JavaScript function that runs as soon as it is defined It is also called a Self - Executing Anonymous Function The first is the anonymous function with lexical scope enclosed within the Grouping Operator() This prevents accessing variables within the IIFE idiom…