The power of proxies, however, lies in the ability to define traps. Any interactions performed on the proxy are by default forwarded to the target, as if we’re still interacting directly with the target.

What are Proxies?Ī Proxy is an object that essentially wraps any other object (called the target). Instead, we have to write some verbose code to get the last item of the array, for example: // JavaScript: const letters = letters // => 'e'įortunately, using Proxies, we can support accessing our array items starting from the end using negative indexes.

This behavior is not available is JavaScript by default. In other programming languages, Python for instance, we can use negative indexes to access items from the end of an array: # Python: letters = letters // => 'a' letters // => 'e' JavaScript: const letters = letters // => 'a' letters // => 'c' letters // => undefined These indexes are non-negative integers, and accessing a negative index will just return undefined.

JavaScript arrays are collections of items, where each item is accessible through an index.

Javascript for each index