Elegant way of creating an array of arrays?

Question

I want to create an array of arrays from another array:

a = [11,1,[23,21],14,[90,1]]
a.map { |e| e.is_a?(Array) ? e : [e] }
# => [[11], [1], [23, 21], [14], [90, 1]]

Is there an elegant way to do this?

What's wrong with how you're doing it? Looking at what you're getting in your result makes me think there's another problem underneath this that should be fixed. Receiving an array of the form that yours is hints of code smell and you're trying to work around it instead of addressing the problem of getting single elements mixed with sub-arrays. — the Tin Man
– the Tin Man, Commented Feb 22, 2014 at 4:39
@Arup's answer is great, but it is also worth noting that you can rapleace is_a? with ===. cf. stackoverflow.com/questions/3422223/vs-in-ruby — nodakai
– nodakai, Commented Feb 22, 2014 at 4:51

Arup Rakshit · Accepted Answer · 2014-02-22 01:02:07Z

6

I would do as below :

a = [11,1,[23,21],14,[90,1]]
a.map { |e| [*e] }
# => [[11], [1], [23, 21], [14], [90, 1]]

a.map { |e| Array(e) }
# => [[11], [1], [23, 21], [14], [90, 1]]

Use, which ever you think as elegant, for me both are elegant :-)

answered Feb 22, 2014 at 1:02

Arup Rakshit

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4 Comments

Great ideas!.. I'll catch you in the morning.. very sleepy (3:00 am here)

Here 6-40 am :-) @Abdo

Nice, Arup. I'll have to remember those two little gems.