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Discussion on: Understanding Ruby - Enumerable - Transformations

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grumbleafrican profile image
grumbleafrican • • Edited

Minor comment around the one example...

hands.flat_map(&:cards).map(&:to_s).join(', ')
# => "S2, S3, S4, S3, S4, S5, S4, S5"
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#join (doc) calls #to_s on the object, so that extra map is not useful.

irb(main):001:0> [:a, :b, :c].join(',')
=> "a,b,c"
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baweaver profile image
Brandon Weaver •

True, and easy to forget it does that. It also flattens collections:

[[1], 2, 3, [[[4, 5], 6], 7]].join(', ')
# => "1, 2, 3, 4, 5, 6, 7"
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