Ruby way to query over a json object

Question

I have the following json string:

[{"name": "John", "room": "A"},
 {"name": "Nick", "room": "A"},
 {"name": "Bill", "room": "B"}]

How can I extract the records whose "room" value equals "A" without iterating over all of them explicitly?

I'm looking for a simple way to search over elements.

possible duplicate of [Accessing elements of nested hashes in ruby](http://stackoverflow.com/questions/5544858/accessing-elements-of-nested-hashes-in-ruby) — Roman Kiselenko, Jul 23 '15 at 08:55
@paulo : then check my answer it is suitable for your requirement. Also check the reference as well. — Gagan Gami, Jul 23 '15 at 09:05

Gagan Gami · Accepted Answer · 2015-07-23T09:02:42.453

1

> array.select{|a| a[:room] == "A"}
#=> [{:name=>"John", :room=>"A"}, {:name=>"Nick", :room=>"A"}]

edited Jul 23 '15 at 09:02

answered Jul 23 '15 at 08:57

Gagan Gami

1

I am not sure whether OP wanted to avoid this. – sawa Jul 23 '15 at 08:59
@sawa : Why? Is OP expected anything else – Gagan Gami Jul 23 '15 at 09:00
The OP wrote they wanted to avoid explicitly iterating over. It is not clear what that means, but your answer may be such case. – sawa Jul 23 '15 at 09:02
@sawa : yes you are right. Even I m also confused with that but I assume generally he want this only. If OP make clear so I can modify my answer as per his requirement. – Gagan Gami Jul 23 '15 at 09:03
1

So, since there's no explicit `.each` in the code above, this does qualify per OP's definition. While it does (internally) iterate through, doing otherwise is practically impossible :} – D-side Jul 23 '15 at 09:07
1

@D-side but it's **iterate** over an array. – Roman Kiselenko Jul 23 '15 at 09:09
@D-side : Is there any other best way then love to see as post. – Gagan Gami Jul 23 '15 at 09:11
1

@GaganGami I believe yours is *the one*. The array structure implies this can't be done more efficiently anyway. If that were something else, there would be room for thought. – D-side Jul 23 '15 at 09:12

1 Answers1