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1. stackoverflow.com › questions › 31069453Creating a (ES6) promise without starting to resolve it

   stackoverflow.com › questions › 31069453

   Jun 26, 2015 · Using ES6 promises, how do I create a promise without defining the logic for resolving it? Here's a basic example (some TypeScript): var promises = {}; function waitFor(key: string): Promise<an...

2. stackoverflow.com › questions › 26150232javascript - How can I access Promise resolution callbacks ...

   stackoverflow.com › questions › 26150232

   Resolving Promise without executor from outside: const promise = Promise.exposed().then(console.log); promise.resolve("This should show up in the console."); Racing with the executor's setTimeout from outside:

3. stackoverflow.com › questions › 35008607javascript - Resolving a Promise without calling the 'then ...

   stackoverflow.com › questions › 35008607

   Jan 26, 2016 · var promise = new Promise(function (resolve, reject) { /*....*/}); if (typeof cb === 'function') { promise.then(cb); } else { return promise; }

4. developer.mozilla.org › Promise › resolvePromise.resolve() - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org › Promise › resolve

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   • Overview
   • Syntax
   • Description
   • Examples
   • Browser compatibility

   The Promise.resolve() static method "resolves" a given value to a Promise. If the value is a promise, that promise is returned; if the value is a thenable, Promise.resolve() will call the then() method with two callbacks it prepared; otherwise the returned promise will be fulfilled with the value.

   This function flattens nested layers of promise-like objects (e.g. a promise that fulfills to a promise that fulfills to something) into a single layer — a promise that fulfills to a non-thenable value.

   See full list on developer.mozilla.org

   Parameters

   value Argument to be resolved by this Promise. Can also be a Promise or a thenable to resolve.

   Return value

   A Promise that is resolved with the given value, or the promise passed as value, if the value was a promise object. A resolved promise can be in any of the states — fulfilled, rejected, or pending. For example, resolving a rejected promise will still result in a rejected promise.

   See full list on developer.mozilla.org

   Promise.resolve() resolves a promise, which is not the same as fulfilling or rejecting the promise. See Promise description for definitions of the terminology. In brief, Promise.resolve() returns a promise whose eventual state depends on another promise, thenable object, or other value.

   Promise.resolve() is generic and supports subclassing, which means it can be called on subclasses of Promise, and the result will be a promise of the subclass type. To do so, the subclass's constructor must implement the same signature as the Promise() constructor — accepting a single executor function that can be called with the resolve and reject callbacks as parameters.

   Promise.resolve() special-cases native Promise instances. If value belongs to Promise or a subclass, and value.constructor === Promise, then value is directly returned by Promise.resolve(), without creating a new Promise instance. Otherwise, Promise.resolve() is essentially a shorthand for new Promise((resolve) => resolve(value)).

   The bulk of the resolving logic is actually implemented by the resolve function passed by the Promise() constructor. In summary:

   •If a non-thenable value is passed, the returned promise is already fulfilled with that value.

   •If a thenable is passed, the returned promise will adopt the state of that thenable by calling the then method and passing a pair of resolving functions as arguments. (But because native promises directly pass through Promise.resolve() without creating a wrapper, the then method is not called on native promises.) If the resolve function receives another thenable object, it will be resolved again, so that the eventual fulfillment value of the promise will never be thenable.

   See full list on developer.mozilla.org

   Using the static Promise.resolve method

   Resolving an array

   Resolving another Promise

   Promise.resolve() reuses existing Promise instances. If it's resolving a native promise, it returns the same promise instance without creating a wrapper. The inverted order of the logs is due to the fact that the then handlers are called asynchronously. See the then() reference for more information.

   Resolving thenables and throwing Errors

   Nested thenables will be "deeply flattened" to a single promise.

   Calling resolve() on a non-Promise constructor

   Promise.resolve() is a generic method. It can be called on any constructor that implements the same signature as the Promise() constructor. For example, we can call it on a constructor that passes it console.log as resolve: The ability to flatten nested thenables is implemented by the resolve function of the Promise() constructor, so if you call it on another constructor, nested thenables may not be flattened, depending on how that constructor implements its resolve function.

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5. www.freecodecamp.org › news › javascript-promiseJavaScript Promise Tutorial – How to Resolve or Reject ...

   www.freecodecamp.org › news › javascript-promise

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   Dec 15, 2020 · let promise = new Promise(function(resolve, reject) { // Make an asynchronous call and either resolve or reject }); In most cases, a promise may be used for an asynchronous operation. However, technically, you can resolve/reject on both synchronous and asynchronous operations.

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6. developer.mozilla.org › en-US › docsUsing promises - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org › en-US › docs

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   Oct 7, 2024 · The promise constructor takes an executor function that lets us resolve or reject a promise manually. Since setTimeout() doesn't really fail, we left out reject in this case. For more information on how the executor function works, see the Promise() reference.

7. People also ask

   How to resolve a promise in JavaScript?

   • The most concise solution I found to this issue is Promise.withResolvers() The function returns an object allowing invokation from outside the executor function. Just another solution to resolve Promise from the outside class Lock { #lock; // Promise to be resolved (on release) release; // Release lock id; // Id of lock constructor(id) {

   How can I access Promise resolution callbacks outside the Promise

   stackoverflow.com/questions/26150232/how-can-i-access-promise-resolution-callbacks-outside-the-promise-constructor-ca

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   How do you return a new promise in JavaScript?

   • return [ new Promise((resolve, reject) => { resolver = resolve; }), resolver, ]; We are essentially grabbing the reference to the resolve function when the promise is created, and we return that so it can be set externally.

   How can I access Promise resolution callbacks outside the Promise

   stackoverflow.com/questions/26150232/how-can-i-access-promise-resolution-callbacks-outside-the-promise-constructor-ca

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   How do you call a promise in JavaScript?

   • let promise = newPromise(function(resolve, reject) { reject (newError('Something is not right!')); }); An important point to note: A Promise executor should call only one resolve or one reject. Once one state is changed (pending => fulfilled or pending => rejected), that's all. Any further calls to resolve or reject will be ignored.

   JavaScript Promise Tutorial – How to Resolve or Reject Promises in JS

   www.freecodecamp.org/news/javascript-promise-tutorial-how-to-resolve-or-reject-promises-in-js/

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   What is a promise in JavaScript?

   • A Promise is a special JavaScript object. It produces a value after an asynchronous (aka, async) operation completes successfully, or an error if it does not complete successfully due to time out, network error, and so on. Successful call completions are indicated by the resolve function call, and errors are indicated by the reject function call.

   JavaScript Promise Tutorial – How to Resolve or Reject Promises in JS

   www.freecodecamp.org/news/javascript-promise-tutorial-how-to-resolve-or-reject-promises-in-js/

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   How do I create a new promise in JavaScript?

   • It's actually very straightforward. Only you may have missed it because it's hidden amongst that tangle of code. Basically you do this: var promise = new Promise(function (resolve, reject) { /*....*/}); promise.then(cb); return promise;

   Resolving a Promise without calling the 'then' - Stack Overflow

   stackoverflow.com/questions/35008607/resolving-a-promise-without-calling-the-then

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   How do I reject a promise if something is not right?

   • The promise below will be rejected (rejected state) with the error message Something is not right!. let promise = newPromise(function(resolve, reject) { reject (newError('Something is not right!')); }); An important point to note: A Promise executor should call only one resolve or one reject.

   JavaScript Promise Tutorial – How to Resolve or Reject Promises in JS

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8. developer.mozilla.org › en-US › docsPromise - JavaScript | MDN - MDN Web Docs

   developer.mozilla.org › en-US › docs

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   Oct 7, 2024 · Promise.resolve() Returns a Promise object that is resolved with the given value. If the value is a thenable (i.e. has a then method), the returned promise will "follow" that thenable, adopting its eventual state; otherwise, the returned promise will be fulfilled with the value. Promise.try() Experimental