Description: Promise.allSettled is a method in JavaScript that returns a promise that resolves after all of the given promises have either resolved or rejected. This method is particularly useful in situations where you need to wait for a set of asynchronous operations to complete, regardless of whether each one succeeded or failed. Unlike Promise.all, which rejects as soon as one of the promises is rejected, Promise.allSettled allows you to handle each result individually. The result is an array of objects that describe the outcome of each promise, where each object contains two properties: ‘status’ (which can be ‘fulfilled’ or ‘rejected’) and ‘value’ or ‘reason’, depending on whether the promise was resolved or rejected. This feature makes it a valuable tool for error handling and collecting results from multiple asynchronous operations, facilitating the implementation of more robust and flexible logic in modern JavaScript applications.
History: Promise.allSettled was introduced in ECMAScript 2020 (ES11) as part of an effort to improve promise management in JavaScript. Prior to its inclusion, developers often had to implement custom solutions to handle multiple promises and their results, which could lead to more complex and error-prone code. The addition of Promise.allSettled allowed developers to more efficiently handle the results of multiple asynchronous operations, simplifying workflows and improving code readability.
Uses: Promise.allSettled is commonly used in situations where you need to wait for a set of promises to complete, such as loading multiple resources, executing several API requests, or performing asynchronous tasks in parallel. It is especially useful in web applications where you need to gather results from different sources and handle errors effectively, without the failure of a single operation affecting the others.
Examples: A practical example of Promise.allSettled would be loading multiple resources from a server. By using Promise.allSettled, you can wait for all resources to load, and then handle each result individually, displaying those that loaded successfully and handling errors for those that failed without interrupting the loading process of the others.
