Misc #14147: Array#sample documentation is unclear about order

• Status: Closed
• Priority: Normal
• Assignee: -

[StefanPochmann (Stefan Pochmann)]

Does Array#sample only guarantee a random subset, or also random order? It's not clear. I think the current reference implementation does produce random order, but the documentation doesn't guarantee it, so I can't rely on it. If random order is intended, I think the documentation should say so. Maybe say that sample(n) is equivalent to shuffle.take(n)? ("equivalent" meaning same possible outputs with same probabilities)

More details here: https://stackoverflow.com/q/47600931/1672429

[shevegen (Robert A. Heiler)]

I agree; I think the documentation should mention that at http://ruby-doc.org/core/Array.html#method-i-sample. One can look at the source there :) but ... I guess more people will understand an explanation of the code, rather than the C code itself. :D

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed

Applied in changeset git|f8bf766877782468c4da8c1cecaf21ce9eac3684.

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[DOC] Additional to Array#sample [ci skip]

• The requirement to the n argument.
• The order of the result array. [Misc #14147]