Fascinating

smart way!

Well here Array is an object and Object.assign does what it's name tells us, it assigns or say inserts the given properties to the given object.
As here we are assigning those square, cube etc properties to the Array.prototype object.

Hope you get it?
else do let me know, I will give you some examples!

BTW CLEVER code!

Can anyone tell me how is Object.assign() working here

Nice catch of using Object.assign in order to avoid accessing the Array prototype repetitive