What is a Closure in JavaScript?

Answer: A closure refers to a JavaScript feature that allows an inner function to access the variables of its outer (enclosing) function, creating a scope chain. Closures are instrumental for achieving privacy, encapsulation, and for constructing function factories and module patterns.

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Explain the difference between var, let, and const.

Answer: The distinctions among var, let, and const primarily revolve around their scope and reassignment capabilities. The var keyword is function-scoped, while both let and const are block-scoped. Variables declared with var can be redeclared and updated, let variables can be updated but not redeclared within the same scope, and const variables are immutable and cannot be redeclared.

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How do Promises function in JavaScript?

Answer: Promises are objects that symbolize the eventual resolution or rejection of an asynchronous operation. They simplify the writing of asynchronous code, making it cleaner and more comprehensible by avoiding callback hell. A promise can be in one of three states: pending, fulfilled, or rejected.

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What is the Event Loop in JavaScript?

Answer: The event loop is the mechanism that enables JavaScript to carry out non-blocking asynchronous operations. Despite being single-threaded, JavaScript utilizes the event loop to manage multiple operations through the call stack, event queue, and web APIs. It continually checks the call stack and pushes the first event from the queue to the stack when the call stack is empty.

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Explain Prototypal Inheritance in JavaScript.

Answer: Prototypal inheritance allows objects in JavaScript to inherit properties and methods from other objects. Unlike classical inheritance, JavaScript leverages a prototype chain to facilitate shared functionality between objects.

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What are Arrow Functions?

Answer: Arrow functions provide a streamlined syntax for defining function expressions in JavaScript. They do not possess their own context for this, arguments, super, or new.target. Instead, they are lexically bound, meaning they adopt the this value from their enclosing lexical context.

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Explain the concept of Hoisting in JavaScript.

Answer: Hoisting is the behavior in JavaScript that elevates declarations to the top of their containing scope. This allows functions or variables to be invoked before their declaration appears in the code. It’s important to note that only the declarations are hoisted, not their initial values.

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What does the this keyword represent in JavaScript?

Answer: The this keyword points to the object that is currently executing the code. Its value is contingent upon how the function is invoked. It may refer to a global object, the object that invokes the method, or an object instantiated by a constructor.

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These interview questions and answers provide valuable insight into the essential aspects of JavaScript. They encompass fundamental concepts and features vital for any aspiring JavaScript developer.

This video, titled "8 | Javascript Coding Challenge Interview Questions 2022," offers a series of coding challenges focused on JavaScript interview questions, helping candidates sharpen their skills.

The video "Javascript Interview Questions and Answers - 8" presents a comprehensive overview of common JavaScript interview questions along with detailed answers to enhance your understanding.