Explain the concept of prototypal inheritance in JavaScript.

Prototypal inheritance is a fundamental concept in JavaScript that allows objects to inherit properties and methods from other objects. It is a key feature of JavaScript’s object-oriented programming paradigm. In JavaScript, every object has an internal property called [[Prototype]] (also referred to as “dunder proto” or “proto”). This [[Prototype]] property references another object, which is … Read more

What are JavaScript promises? How do they work?

JavaScript promises are objects used for handling asynchronous operations. They represent the eventual completion (or failure) of an asynchronous operation and allow you to write more readable and maintainable asynchronous code. Promises work based on the concept of “callbacks.” Traditionally, callbacks were used to handle asynchronous operations, but they can result in callback hell and … Read more

What is the difference between == and === operators?

What is the difference between == and === operators? In JavaScript, the == (loose equality) and === (strict equality) operators are used for comparison, but they behave differently in terms of how they handle type coercion and equality checks. Here’s a detailed explanation of the differences between these operators: Loose Equality (==) Operator: The == … Read more

Explain the event delegation in JavaScript.

Explain the event delegation in JavaScript. Event delegation is a technique in JavaScript where instead of attaching an event handler to each individual element, you attach a single event handler to a parent element and handle the events of its child elements through event bubbling. This approach has several benefits, such as improved performance, reduced … Read more

What are the differences between var, let, and const?

What are the differences between var, let, and const? In JavaScript, var, let, and const are used to declare variables, but they have different scoping rules and behaviors. Here’s a detailed explanation of the differences between them: var: Variables declared with var are function-scoped or globally-scoped. They are hoisted to the top of their scope, … Read more

What is the difference between null and undefined in JavaScript?

In JavaScript, null and undefined are both special values that represent the absence of a value. However, they have different use cases and behaviors. Here’s a detailed explanation of the difference between null and undefined: undefined: undefined is a primitive value in JavaScript. It is used to indicate the absence of an assigned value to … Read more

What are the different data types in JavaScript?

What are the different data types in JavaScript? JavaScript has several built-in data types that are used to represent different kinds of values. Here are the different data types in JavaScript: Number:  Represents numeric values. It can be an integer or a floating-point number. For example: var age = 25; var temperature = 98.6; String:  … Read more

How do I make an HTTP request in Javascript

In JavaScript, you can make an HTTP request using the XMLHttpRequest object or the newer fetch() function. Here’s an example of how to make an HTTP GET request using both methods: Using XMLHttpRequest: var xhr = new XMLHttpRequest(); xhr.open(“GET”, “https://api.example.com/data”, true); xhr.onreadystatechange = function() { if (xhr.readyState === 4 && xhr.status === 200) { var … Read more