Promise Methods

JavaScript · Methods reference

JavaScript · Methods reference

📋 Overview

Promise constructor and static combinators for async control flow.

🔧 Methods

Instance

Method	Description
`then(onFulfilled?, onRejected?)`	Chain on fulfillment/rejection
`catch(onRejected)`	Handle rejection
`finally(onFinally)`	Run on settle either way

Static

Method	Description
`Promise.resolve(value)`	Fulfilled promise
`Promise.reject(reason)`	Rejected promise
`Promise.all(iterable)`	All fulfill or first reject
`Promise.allSettled(iterable)`	Wait for all; never rejects
`Promise.race(iterable)`	First settled wins
`Promise.any(iterable)`	First fulfill; AggregateError if all reject
`Promise.withResolvers()`	Deferred {promise, resolve, reject} (ES2024)

💡 Examples

See parent topic notes for runnable snippets; this page is the complete method index.

⚠️ Pitfalls

Mutating methods return None in Python — do not chain sort() / reverse() expecting a new list.
Default JS sort() compares strings — pass (a,b) => a-b for numbers.
SQL function names differ by dialect — verify Postgres vs MySQL docs.
Django QuerySet.update() skips save() signals and auto auto_now fields on models.

Async

Object Static Methods

JavaScript · Methods reference

String Methods

JavaScript · Methods reference

On this page

📋 Overview 🔧 Methods Instance Static 💡 Examples ⚠️ Pitfalls 🔗 Related