# IO#puts and arrays

**URL:** <https://www.ruby-forum.com/t/io-puts-and-arrays/94611>\
**Category:** Ruby\
**Created:** [May 8, 2006, 11:30pm UTC](https://www.ruby-forum.com/t/io-puts-and-arrays/94611 "2006-05-08T23:30:23Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![dasch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b2d939/32.png) [@dasch](https://www.ruby-forum.com/u/dasch)\
**Post date:** [May 8, 2006, 11:30pm UTC](https://www.ruby-forum.com/t/io-puts-and-arrays/94611/1 "2006-05-08T23:30:23Z")

</div>

Exactly how does IO#puts determine if an argument is an array? That is,  
how do I construct an object that is treated like an Array object by  
IO#puts, preferably without inheriting from Array – I had hoped a  
#to\_arr method would suffice, but alas, it did not.

Daniel

---

<div class="post-metadata">

**Author:** ![dasch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b2d939/32.png) [@dasch](https://www.ruby-forum.com/u/dasch)\
**Post date:** [May 8, 2006, 11:33pm UTC](https://www.ruby-forum.com/t/io-puts-and-arrays/94611/2 "2006-05-08T23:33:44Z")

</div>

Daniel S. wrote:

> Exactly how does IO#puts determine if an argument is an array? That is,  
> how do I construct an object that is treated like an Array object by  
> IO#puts, preferably without inheriting from Array – I had hoped a  
> #to\_arr method would suffice, but alas, it did not.

Oooops, it was #to\_ary, and it’s working like a charm 🙂

Sorry to have bothered you!

Daniel