This Ruby code is not behaving as I would expect:
# create an array of hashes
sort_me = []
sort_me.push({"value"=>1, "name"=>"a"})
sort_me.push({"value"=>3, "name"=>"c"})
sort_me.push({"value"=>2, "name"=>"b"})
# sort
sort_me.sort_by { |k| k["value"]}
# same order as above!
puts sort_me
I'm looking to sort the array of hashes by the key "value", but they are printed unsorted.
Ruby's sort doesn't sort in-place. (Do you have a Python background, perhaps?)
Ruby has sort! for in-place sorting, but there's no in-place variant for sort_by in Ruby 1.8. In practice, you can do:
sorted = sort_me.sort_by { |k| k["value"] }
puts sorted
As of Ruby 1.9+, .sort_by! is available for in-place sorting:
sort_me.sort_by! { |k| k["value"]}
Array#sort_by! is new in Ruby 1.9.2. Available today to all Ruby version by requiring my backports gem too :-)
3,2,1...
sort_by, but use sort or sort! and simply flip the operands: a.sort! {|x,y| y <=> x } (ruby-doc.org/core-1.9.3/Array.html#method-i-sort)
puts sorted = sort_me.sort_by{ |k,v| v }.reverse.As per @shteef but implemented with the sort! variant as suggested:
sort_me.sort! { |x, y| x["value"] <=> y["value"] }
Although Ruby doesn't have a sort_by in-place variant, you can do:
sort_me = sort_me.sort_by { |k| k["value"] }
Array.sort_by! was added in 1.9.2
You can use sort_me.sort_by!{ |k| k["value"]}. This should work.
