I'm learning about the Array from() method in javascript's documentation, and I couldn't know the role of an underscore in the the arguments of this method which made the whole example hard to understand.

The code :

const range = (start, stop, step) => 
Array.from({ length: (stop - start) / step + 1},(_, i) => start + (i * step)); // the underscore before i ?

Can you explain it for me ?

Thanks in advance.