# init(newPromiseIn:fromExecutor:) Creates a promise object using the specified executor callback. ``` init!(newPromiseIn context: JSContext!, fromExecutor callback: ((JSValue?, JSValue?) -> Void)!) ``` ## Parameters `context` The [`JSContext`](/documentation/JavaScriptCore/JSContext) the resulting [`JSValue`](/documentation/JavaScriptCore/JSValue) belongs to. `callback` A callback block to invoke during initialization of the promise object. The `resolve` and `reject` parameters are functions that you can call to notify any pending reactions about the state of the new promise object. ## Return Value A [`JSValue`](/documentation/JavaScriptCore/JSValue) that represents a new promise JavaScript object. ## Discussion This method is equivalent to calling the `Promise()` constructor in JavaScript. The `resolve` and `reject` callbacks each typically take a single value, which they forward to all relevant pending reactions. While inside the executor callback, `context` acts as if it is in any other callback, except `calleeFunction` is `nil`. This also means you can access the new promise object using `[context thisValue]`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)