Ruby Hash Value into Array of Values

Question

I have a hash {:a => b} and I want to add a value to that key and turn it into an array of values keeping the previous one.

So the result would be {:a => [b, c]}

Is there a better way to do this than iterating through the hash?

No :-) You have to iterate anyway, so what is your question? "What is the shortest way to reach ..."? — mliebelt
– mliebelt, Commented Feb 27, 2013 at 14:25

Abibullah Rahamathulah · Accepted Answer · 2013-02-27 14:43:04Z

4

Try This.

h = {a: b}
h[:a] = ((a[:a].is_a? Array) ? a[:a] : [a[:a]]) << c

answered Feb 27, 2013 at 14:26

2,9011 gold badge24 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

The original question doesn't mention whether b might possibly already be an array. If that's possible, you may want add a check.

Benjamin M · Accepted Answer · 2013-02-27 14:25:43Z

0

Simple solution would be to create a Hash of Arrays:

h = {}
h[:a] = []
h[:a].push(b)
h[:a].push(c)

What I mean: Even if there's only one value use an array. That makes handling easier.

answered Feb 27, 2013 at 14:25

Benjamin M

24.7k34 gold badges135 silver badges211 bronze badges