not if you don't know it's a loop

it's a loop, you can google what a loop is

why did you use it in your own solution?

why need toLowerCase here ?

Because these are no valid JavaScript functions. An array instance does not have a property isArray. It is a method on the Array class. Please read the MDN docs.

If you don't know what "?" means, why did you use it in your solution?

(_,i,arr) whats mean _ ?

what is 1 after ?
why 1 + .... ?

I feeling bad right now X_X Better i didnt see that/ My solution now in basket (

why Array.isArray( arr ) ? whats mean Array.isArray if we have arr?
why i cant write (!arr.isArray) return 'It's a fake array' ?
Can someone answer pls :(

How it works ? Can someone write pls :(

Thanks for answer, its really help me understand. Never thought about that solution. Its really great.

:)