How can we add custom property in array prototype in javascript just like length to receive last item of that array? [duplicate]

I am looking for a way to create a new variable in Array prototype in javascript similar to Array.length property. So that I can get the last element just by calling that array property. Something like mentioned below

Example:

const arr = ['a','b','c'];

// Current working property: length
console.log(arr.length) // It will give me 3 and I didn't need to call any function.

// What I want to achieve: lastItem
console.log(arr.lastItem) // It should give me 'c' without calling as a function.

I have a way to get last item by creating a prototype method but I don’t want to call any method to get last value. I want it to be set as property only.