Why does Array.to_s return brackets?

Question

For an array, when I type:

puts array[0]

==> text

Yet when I type

puts array[0].to_s

==> ["text"]

Why the brackets and quotes? What am I missing?

ADDENDUM: my code looks like this

page = open(url)  {|f| f.read }
page_array = page.scan(/regex/) #pulls partial urls into an array
partial_url = page_array[0].to_s
full_url = base_url + partial_url #adds each partial url to a consistent base_url
puts full_url

what I'm getting looks like:

http://www.stackoverflow/["questions"]

What's in your `array`? And which Ruby version are you talking about (there's a difference here between 1.8 and 1.9) — Amadan, Jan 12 '12 at 03:05
Try `p array` and I think you'll get `[["text"]]` output. I'm just guessing. — ian, Jan 12 '12 at 03:39
@Iain but what does that get me? How do I get just the text, without the quotes and brackets? — user1144553, Jan 12 '12 at 03:41
probably [this](http://stackoverflow.com/questions/3960392/ruby-1-9-array-to-s-behaves-differently) will answer your question. — Sufendy, Jan 12 '12 at 04:12
And [this](http://stackoverflow.com/a/1732454/38765) will question your question. — Andrew Grimm, Jan 12 '12 at 04:51

score 21 · Answer 1 · answered Jan 24 '13 at 18:05

21

This print the array as is without brackets

array.join(", ")

answered Jan 24 '13 at 18:05

Erick Eduardo Garcia

1,147
13
17

score 12 · Answer 2 · answered Jan 12 '12 at 05:38

to_s is just an alias to inspect for the Array class.

Not that this means a lot other than instead of expecting array.to_s to return a string it's actually returning array.inspect which, based on the name of the method, isn't really what you are looking for.

If you want just the "guts" try:

page_array.join

If there are multiple elements to the array:

page_array.join(" ")

This will make:

page_array = ["test","this","function"]

return:

"test this function"

What "to_s" on an Array returns, depends on the version of Ruby you are using as mentioned above. 1.9.X returns:

"[\"test\"]"

score 2 · Answer 3 · answered Jan 12 '12 at 03:45

2

You need to show us the regex to really fix this properly, but this will do it:

Replace this

partial_url = page_array[0].to_s

with this

partial_url = page_array[0][0]

answered Jan 12 '12 at 03:45

ian

12,003
9
51
107

Thank you! That did it. But you're right, it was a regex issue. – user1144553 Jan 12 '12 at 03:56

score 1 · Answer 4 · answered Jan 12 '12 at 03:48

This doesn't necessarily fix why you are getting a doubled-up array, but you can flatten it and then call the first element like this.

page_array = page.scan(/regex/).flatten

Flattening takes out stacked arrays and creates one level, so if you had [1,2,[3,[4,5,6]]] and called flatten on it, you would get [1,2,3,4,5,6]

It is also more robust than doing array[0][0], because, if you had more than two arrays nested in the first element, you would run into the same issue.

Iain is correct though, without seeing the regex, we can't suss out the root cause.

Why does Array.to_s return brackets?

4 Answers4

Linked