Missing depth parameter to Array.prototype.flat method about 1loc

[phuocng]

The depth parameter is optional.

[fahimfaisaal]

Then the function should be like this

const flat = (arr, depth = 1) => arr.flat(depth);

[elkarouani]

I think that parameter depends on the use of the array, so it will be changeable not just constant to value 1 for global usage.
It will be an enhancement if the idea was global. In any case, it's an optional (not required) parameter for the method Array.Prototype.flat().