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    A Promise in JavaScript is an object that represents the eventual completion (or failure) of an asynchronous operation and its resulting value. It allows you to write asynchronous code in a more synchronous fashion, making it easier to read and maintain.

    Key Principles

    A Promise can be in one of three states:

    • Pending: The initial state, neither fulfilled nor rejected.

    • Fulfilled: The operation completed successfully.

    • Rejected: The operation failed.

    When a Promise is created, it takes a function as an argument. This function is called the executor function, and it takes two arguments: resolve and reject. The resolve function is called when the operation is successful, and the reject function is called when the operation fails.

    Code Example

    Here is a basic example of creating and using a Promise:

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  3. W3School
    https://www.w3schools.com › Js › js_promise.asp

    JavaScript Promises - W3Schools

    A Promise is an object that links producing code and consuming code in JavaScript. Learn how to create, use and handle promises with examples and browser support.

    See results only from w3schools.com
  4. Mozilla Developer
    https://developer.mozilla.org › en-US › docs › Web › JavaScript › Referenc…

    Promise - JavaScript | MDN - MDN Web Docs

    Sep 18, 2025 · A Promise is an object that represents the eventual completion or failure of an asynchronous operation and its resulting value. Learn how to use promises, their states, methods, …

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  6. FreeCodecamp
    https://www.freecodecamp.org › news › what-is-promise-in-javascript-for...

    What is a Promise? JavaScript Promises for Beginners

    Aug 16, 2021 · Learn what a promise is in JavaScript with a simple story and examples. A promise is a placeholder for an asynchronous task that returns a value or an error later.

  7. GeeksForGeeks
    https://www.geeksforgeeks.org › javascript › javascript-promise

    JavaScript Promise - GeeksforGeeks

    Jul 11, 2025 · JavaScript Promises make handling asynchronous operations like API calls, file loading, or time delays easier. Think of a Promise as a placeholder for a value that will be available in the future.

  8. W3Schools
    https://www.w3schools.in › javascript › promises

    Learn JavaScript Promises - W3Schools

    What Is a JavaScript Promise? JavaScript Promises provide a modern way to handle asynchronous operations such as fetching data from an API, reading files, or working with timers. A Promise is an …

  9. The Modern JavaScript Tutorial
    https://javascript.info › promise-basics

    Promise - The Modern JavaScript Tutorial

    Dec 11, 2024 · A promise is a special object that links the producing code and the consuming code together. Learn how to create, use and handle promises with examples and explanations.

  10. DEV Community
    https://dev.to › itsshaikhaj

    Promises in JavaScript: The Ultimate Guide for Beginners

    Jul 27, 2024 · What is a Promise in JavaScript? A promise in JavaScript is an object representing the eventual completion or failure of an asynchronous operation. It allows you to associate handlers with …

  11. C# Corner
    https://www.c-sharpcorner.com › learn › learn-javascript › promises-in...

    Promises in JavaScript - C# Corner

    As you learned earlier, JavaScript is asynchronous — it does not wait for long tasks like: API calls File loading Database operations Timers User interactions Before Promises were introduced, developers …

  12. Intellipaat
    https://intellipaat.com › blog › javascript-promise

    JavaScript Promises - Intellipaat

    Nov 18, 2025 · In this guide, you will learn what JavaScript Promises are, why they matter, and how they work. We will cover creating JavaScript Promises, chaining them, handling errors, using async/await, …