Converting a hash to array in ruby

Question

I'm fairly new to ruby and I've got a hash that looks like so:

{ ["key1", "key2"] => 5, ["key1", "key3"] => 2, ... }

and I would like to convert it to an array that looks something like

[ ["key1", "key2", 5], ["key1", "key3", 2] ... ]

How would I go about doing this?

Matzi · Accepted Answer · 2012-07-06 07:55:32Z

3

Simply:

hash.collect{|k, v| k << v}

Of if you need the original hash unchanged:

hash.collect{|k, v| k + [v]}

answered Jul 6, 2012 at 7:55

Matzi

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2 Comments

mu is too short Over a year ago

Your first one (or this version of it map { |k, v| k + [v] }) didn't mangle the original Hash's keys.

tokland Over a year ago

nit-picking: variable naming is very important. If you write k you're saying "singular/single-item". If write ks you are saying "plural/collection".

Mladen Jablanović · Accepted Answer · 2012-07-06 09:51:20Z

2

Another way could be:

hash.map(&:flatten)
# => [["key1", "key2", 5], ["key1", "key3", 2]]

answered Jul 6, 2012 at 9:51

Mladen Jablanović

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Comments

soeren · Accepted Answer · 2012-07-06 09:29:44Z

-1

to_a does exactly that.

{ ["key1", "key2"] => 5, ["key1", "key3"] => 2}.to_a

answered Jul 6, 2012 at 9:29

soeren

1

1 Comment

tokland Over a year ago

No, look at the desired output: [ ["key1", "key2", 5], ["key1", "key3", 2] ... ].

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