Coding Challenge Practice - Question 116

The text describes how to implement `Promise.prototype.finally()` that executes a provided callback function regardless of whether the promise resolves or rejects. It achieves this by attaching `.then()` to the input promise and handling both fulfillment and rejection scenarios. When fulfilled, the callback (`onFinally`) is executed, and the original value is returned. When rejected, `onFinally` is executed, and the original error is re-thrown to maintain the rejection state. The provided code snippet demonstrates the implementation using `Promise.resolve` and handling both success and failure cases.