As an aspiring JavaScript developer, it’s crucial not only to know the right questions but also to have well-founded answers to them. Here are ten frequently asked interview questions with detailed answers:
What is the Difference Between “Threading” and “Event-Loop” in JavaScript?
In JavaScript, “Threading” refers to parallel processes, while the “Event-Loop” is a waiting loop that responds to messages. JavaScript uses a single-threaded Event-Loop to enable asynchronous operations without relying on multiple threads. This peculiarity makes JavaScript particularly efficient for event-driven applications.
Can You Explain the Term “Prototypal Inheritance” and How Is It Used in JavaScript?
Prototypal inheritance is a core concept in JavaScript, where objects inherit properties and methods from a prototype object. Each JavaScript object has a prototype from which it inherits methods and properties, allowing for efficient object creation and inheritance.
Memoization is an optimization technique in JavaScript aimed at storing the results of expensive function calls and making them reusable for repeated calls. This can significantly improve performance by avoiding calculations that were previously carried out.
An IIFE is a function that is executed immediately after its definition. This concept is frequently used in JavaScript to limit the scope of variables and prevent them from becoming global. It contributes to structuring the code and avoiding naming conflicts.
How Can You Execute Asynchronous Code Sequentially in JavaScript Without Callback Hell or Too Many Nested Promises?
In JavaScript, asynchronous operations can be implemented sequentially using async/await. This syntax allows you to write asynchronous code in a way that resembles sequential execution without the complexity of nested callbacks or promises.
What Are the Differences Between WeakMap and WeakSet and in What Scenarios Are They Useful?
WeakMap and WeakSet in JavaScript are collections that hold weak references to their elements. WeakMap stores key-value pairs, where the keys are weakly referenced. WeakSet is a collection of objects with weak references. They are useful in scenarios to avoid memory leaks and release objects when they are no longer needed.
Explain the Term “Closure Memory Leak” and How Can You Prevent or Fix It in JavaScript?
A Closure Memory Leak in JavaScript occurs when a function accesses external variables outside its own scope, thereby preventing their release. This problem can be prevented by deleting unnecessary external references as soon as they are no longer needed.
What Is “Currying” in JavaScript and How Is It Implemented?
Currying in JavaScript is a technique where a function is split into a sequence of functions, each with one argument. This technique is often implemented using recursive functions or higher-order functions and facilitates partial application of functions.
Can You Explain the Difference Between “Shallow Copy” and “Deep Copy” in JavaScript and How Are They Created?
A Shallow Copy in JavaScript creates a new copy of an object, but only on the top level. In contrast, a Deep Copy creates a complete copy of an object, including all nested objects. Shallow Copies can be created using methods like Object.assign(), while Deep Copies require their own recursive logic.
Web Workers are standalone JavaScript threads that perform tasks in parallel, thus not blocking the main UI thread. They improve the performance of web applications by carrying out computationally intensive tasks in the background, enabling multithreading in web applications.
Why Registering on Js-Dev.tech Makes Sense
As a JavaScript Developer, it’s important not only to be technically proficient but also to be part of an active community. Js-Dev.tech offers you a platform to network with other experts, benefit from their experiences, and access exclusive projects and resources. By registering on Js-Dev.tech, you can advance your career as a JavaScript developer and become part of a dynamic and supportive community.
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