How to crop a 2D array into a rectangle shape?

Question

Arrays

Who knows the function that would be able to cut a two-dimensional array in the form of a rectangle. That would be possible to specify the place from where to cut and to where.

or if anyone knows explain how to cut in the shape of a rectangle using this function

function CutMap(mat, x, y, w, h) {
        return mat.slice(y, y + h).map(function(row) {
            return row.slice(x, x + w)
        })
    }

Answer 1

Look at the description of the slice and map methods and try to guess what exactly the code you provided does.