Array-like objects
The term array-like object refers to any object that doesn’t throw during the length conversion process described above. In practice, such object is expected to actually have a length property and to have indexed elements in the range 0 to length - 1 . (If it doesn’t have all indices, it will be functionally equivalent to a sparse array.)
You need a length property and the keys need to be numbers in the correct range.
So keys should only be numbers
Not even strings?
Right?
Sorry that I am asking without doing practice as I am out of station.
Due to the quest I am asking you.