# Number of items in a list

**URL:** <https://boards.straightdope.com/t/number-of-items-in-a-list/613555>\
**Category:** Factual Questions\
**Created:** [February 21, 2012, 7:54pm UTC](https://boards.straightdope.com/t/number-of-items-in-a-list/613555 "2012-02-21T19:54:19Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\
**Post date:** [February 21, 2012, 7:54pm UTC](https://boards.straightdope.com/t/number-of-items-in-a-list/613555/1 "2012-02-21T19:54:19Z")

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Can a list contain:

[ul]  
[li]Only one item?[/li][li]Zero items?[/li][li](Hi Opal!)[/li][/ul]

And still be considered a list?

I participated in an interesting philosophical debate about this at work today (which is yet unresolved).

Most of the dictionary definitions for ‘list’ discuss it on the assumption that it contains multiple items, or that one item follows another (which can’t happen with less than two items), but it seems there are some contexts in which a list might still be considered a list, even if it only contains one item, or none.

Can’t think of a very formal scenario, but the ignore and friends lists on this message boards are still lists, even if you have only one thing in them, or none.

And if I sit down to write a shopping list, but in the end, find I only need to buy one item, it’s still a shopping list. If my shopping list contains a dozen items and I cross them off as I pick them, is it still a list when I am down to the last item?

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**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\
**Post date:** [February 21, 2012, 7:57pm UTC](https://boards.straightdope.com/t/number-of-items-in-a-list/613555/2 "2012-02-21T19:57:30Z")

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It really depends on context. In computer programming we think nothing of dealing with zero- and one-element lists all the time. In everyday life, a shopping list or task list could certainly contain one item.

On the other hand, you don’t really have a shopping list if there are zero items to buy.

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**Author:** ![njtt](https://avatars.discourse-cdn.com/v4/letter/n/ecd19e/32.png) [@njtt](https://boards.straightdope.com/u/njtt)\
**Post date:** [February 21, 2012, 7:57pm UTC](https://boards.straightdope.com/t/number-of-items-in-a-list/613555/3 "2012-02-21T19:57:56Z")

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> [@Mangetout](#):
>
> Can a list contain:
> 
> [ul]  
> [li]Only one item?[/li][li]Zero items?[/li][li](Hi Opal!)[/li][/ul]
> 
> And still be considered a list?

In LISP (the AI programming language) it can. The name means “LISt Processing”.