Comment by stevefan1999

The definition of a function is that for any given input A, I give you an output B. In fact anything that encodes a kind of transformation and yield new information based an input could be seen as a function. From that point of view, array is a function that when "touched", it gives you the information about its items.

In fact, from wikipedia:

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In mathematics, a tuple is a finite sequence or ordered list of numbers or, more generally, mathematical objects, which are called the elements of the tuple. An n-tuple is a tuple of n elements, where n is a non-negative integer. There is only one 0-tuple, called the empty tuple. A 1-tuple and a 2-tuple are commonly called a singleton and an ordered pair, respectively. The term "infinite tuple" is occasionally used for "infinite sequences".

Tuples are usually written by listing the elements within parentheses "( )" and separated by commas; for example, (2, 7, 4, 1, 7) denotes a 5-tuple. Other types of brackets are sometimes used, although they may have a different meaning.[a]

An n-tuple can be formally defined as the image of a function that has the set of the n first natural numbers as its domain. Tuples may be also defined from ordered pairs by a recurrence starting from an ordered pair; indeed, an n-tuple can be identified with the ordered pair of its (n − 1) first elements and its nth element

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(https://en.wikipedia.org/wiki/Tuple)

From a data structure standpoint, a tuple can be seen as an array of fixed arity/size, then if an array is not a function, so shouldn't a tuple too.