Ruby: string to array of integers

Question

I want to convert a string into an array of integers. Why do I get an array of strings? What's the right way to achieve the result I'm looking for?

"1234".chars.each { |n| n.to_i }

=> ["1", "2", "3", "4"]

Marek Lipka · Accepted Answer · 2015-02-05 09:05:32Z

5

It's because each return the same array on which it was called. You need map here:

'1234'.chars.map(&:to_i)

which is a shorthand notation to:

'1234'.chars.map { |el| el.to_i }

and returns:

# => [1, 2, 3, 4]

As Cary Swoveland suggested, you can also use each_char method to prevent creation of additional array (each_char returns an enumerator):

'1234'.each_char.map(&:to_i)

answered Feb 5, 2015 at 8:05

Marek Lipka

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3 Comments

Perhaps each_char to avoid the creation of a temporary array.

@CarySwoveland it's your idea. Why don't you add it as an alternative answer? :)

Because it is a tiny detail.