JavaScript
each item must have at least three categorical attributes and at
least one numeric attribute.
Write a function that counts the number of values each item
attribute has. This is effectively a group-by on the item table for
each column. For example: if the first attribute is colour, and its
values are [ ‘red’, ‘black’, ‘white’, ‘black’, ‘red’ ],
the counts for colour would be: red 2 black 2 white 1