What is the difference between JavaScript's equality operators?
Learn all you need to know about the differences between JavaScript's double equals and triple equals operators.
JavaScript Interview Questions
Preparing for a job interview requires studying to refresh your knowledge and skills. This collection of JavaScript interview questions is designed to cover some commonly-asked interview questions, using concise answers and simple examples.
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JavaScript · What are truthy and falsy values in JavaScript?
JavaScript uses type coercion in Boolean contexts, resulting in truthy or falsy values. Get a hang of how it all works in this quick guide.
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JavaScript · What is the difference between an expression and a statement in JavaScript?
JavaScript distinguishes expressions and statements. Learn their differences in this short article.
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JavaScript · What's the difference between undeclared, undefined and null in JavaScript?
JavaScript has three different empty states for variables. Learn their differences and how you can check for each one.
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JavaScript · What is hoisting in JavaScript?
Hoisting comes up a lot during JavaScript interviews. It's a concept that may require some getting used to, so read our guide to learn more.
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JavaScript · Understanding JavaScript variables and scopes
JavaScript developers often get confused by JavaScript's variables and scope. Here's a quick guide to understanding these concepts.
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JavaScript · What is a callback function?
JavaScript uses callback functions quite a lot. From event listeners to asynchronous code, they're an invaluable tool you need to master.
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JavaScript · Is JavaScript pass-by-value or pass-by-reference?
How JavaScript handles passing data is a source of confusion and bugs for many developers, especially when it comes to object types.
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JavaScript · What are promises in JavaScript? In which states can a promise be?
JavaScript's promises represent the eventual completion (or failure) of asynchronous operations and their resulting value.
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JavaScript · What is the difference between synchronous and asynchronous code in JavaScript?
Understanding the differences between synchronous and asynchronous code is a crucial piece of knowledge for every web developer.
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JavaScript · How does JavaScript's prototypal inheritance differ from classical inheritance?
Understanding the difference between these two object-oriented programming paradigms is key to taking your skills to the next level.
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JavaScript · Understanding the "this" keyword in JavaScript
JavaScript's
thiskeyword can confuse beginners and veterans alike. Learn how it works in different scenarios and start using it correctly. -
JavaScript · How can I clone an object in JavaScript?
Learn how JavaScript handles mutable data, such as objects and arrays, and understand how shallow cloning and deep cloning work.
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JavaScript · How can I clone an array in JavaScript?
Pick up a few new tricks which you can use to clone arrays in JavaScript.
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JavaScript · How do I compare two objects in JavaScript?
Learn how you can compare two objects in JavaScript using various different techniques.
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JavaScript · How do I compare two arrays in JavaScript?
Learn how you can compare two arrays in JavaScript using various different techniques.
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JavaScript · How can I check if a JavaScript array includes a specific value?
Checking if an array includes a specific value is pretty straightforward, except when it comes to objects.
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JavaScript · What is the difference between Array.prototype.map() and Array.prototype.forEach()?
Which method do you reach for first? What are the differences between them? Let's find out!
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JavaScript · Understanding event bubbling, capturing and delegation in JavaScript
Understand how events work in JavaScript and learn when to use event bubbling, event capturing and event delegation with this short guide.
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JavaScript · What is the only value not equal to itself in JavaScript?
Did you know there's a JavaScript value that's not equal to itself?
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JavaScript · How can I check for a blank value in JavaScript?
JavaScript doesn't have a built-in way to check if a value is blank, but it's easy to create one.
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JavaScript · Are JavaScript strings immutable?
When it comes to immutability, JavaScript strings are often a source of confusion. Yet they're not as complicated as you might expect.
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JavaScript · What is the difference between static and instance methods?
Static and instance methods are pretty easy to distinguish and serve different purposes. Learn all about them in this article.
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JavaScript · Introduction to arrow functions in JavaScript
JavaScript arrow functions are a very useful tool to learn and master. Here's a complete introduction to everything you need to know.