What are the new features in ECMAScript 2023?

What are the new features in ECMAScript 2023?

ECMAScript 2023 introduces several exciting features, including the new Array.prototype.findLast and findLastIndex methods, which allow you to find elements in an array from the end. Additionally, there are improvements to the WeakRefs and FinalizationRegistry.

Can you explain how findLast works?

Sure! The findLast method returns the value of the last element in the array that satisfies the provided testing function. If no values satisfy the testing function, it returns undefined. For example: array.findLast(x => x < 10) will return the last element less than 10.

What about the WeakRefs improvements?

The improvements to WeakRefs allow for better memory management by enabling developers to hold weak references to objects without preventing them from being garbage collected. This is useful for caching and other scenarios where you want to avoid memory leaks.

Are there any changes to the FinalizationRegistry?

Yes, the FinalizationRegistry now has better support for tracking the finalization of objects, allowing developers to perform cleanup actions when an object is garbage collected. This enhances the ability to manage resources effectively.