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.
Code Articles
30 seconds of code contains a curated collection of code articles covering a wide range of development needs. The collection spans many topics, ranging from simple coding problems to theoretical concepts and development techniques.
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JavaScript · What are the differences between arrow functions and regular functions in JavaScript?
JavaScript's arrow functions are seemingly the same as regular functions, but there are some important differences you need to know.
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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 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 · How can I implement a singleton in JavaScript?
Learn how to implement the singleton design pattern in JavaScript, using the Proxy object.
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CSS · How can I create a custom responsive favicon for dark mode?
Learn how to create a custom responsive favicon that can adapt its color palette for dark mode with this quick guide.
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JavaScript · Can I use an object as an array without modifying it in JavaScript?
Learn how you can leverage the Proxy object to use a JavaScript object the same way as you would use a regular array.
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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 · What are JavaScript Iterators and where can I use them?
Learn how JavaScript's iterators work and how you can use them to level up your projects by understanding these short code 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 · Native JavaScript Data Structures
JavaScript provides a handful of native data structures that you can start using in your code right now.
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JavaScript · JavaScript Data Structures - Binary Search Tree
A binary search tree is a hierarchical data structure of ordered nodes with at most two children each.
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JavaScript · JavaScript Data Structures - Binary Tree
A binary tree is a hierarchical data structure of linked nodes with at most two children each.
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JavaScript · JavaScript Data Structures - Tree
A tree is a data structure consisting of a set of linked nodes representing a hierarchical tree structure.
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JavaScript · JavaScript Data Structures - Graph
A graph is a data structure consisting of a set of vertices connected by a set of edges.
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JavaScript · JavaScript Data Structures - Doubly Linked List
A doubly linked list is a linear data structure where each element points both to the next and the previous one.
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JavaScript · JavaScript Data Structures - Linked List
A linked list is a linear data structure where each element points to the next.
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JavaScript · JavaScript Data Structures - Stack
A stack is a linear data structure which follows a last in, first out (LIFO) order of operations.
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JavaScript · JavaScript Data Structures - Queue
A queue is a linear data structure which follows a first in, first out (FIFO) order of operations.
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JavaScript · Get the index of an array item in a JavaScript for...of loop
Did you know you can get the index of an array item in a JavaScript for...of loop? Learn how with this bite-sized tip.
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Git · How does Git's fast-forward mode work?
Learn about Git's fast-forward mode and its benefits when merging branches, so you can decide if it's a good fit for you and your team.
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JavaScript · Boolean traps and how to avoid them
Boolean traps can cause readability and maintainability issues in your code. Learn what they are, how to spot and fix them in this article.
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JavaScript · Serialize specific properties from a JSON object
Have you ever wanted to serialize an object but only include certain keys? Turns out JavaScript provides an easy way to do this!
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JavaScript · A cautionary tale about JavaScript callbacks
JavaScript callbacks are especially tricky when you're not careful. Take a deeper dive into potential issues and how to avoid them.