Sort hash by key return hash in Ruby

Question

Would this be the best way to sort a hash and return Hash object  instead of Array    h     a   gt 1   c   gt 3   b   gt 2   d   gt 4      gt    a   gt 1   c   gt 3   b   gt 2   d   gt 4   Hash h sort      gt    a   gt 1   b   gt 2   c   gt 3   d   gt 4

User · Answer

I had the same problem   I had to sort my equipments by their name   and i solved like this    lt    equipments sort each do  name  quantity    gt       lt   end   gt     equipments is a hash that I build on my model and return on my controller  If you call  sort it will sort the hash based on it s key value

User · Answer

No  it is not  Ruby 1 9 x   require  benchmark   h     a   gt 1   c   gt 3   b   gt 2   d   gt 4  many   100 000  Benchmark bm do  b    GC start    b report  hash sort   do     many times do       Hash h sort      end   end    GC start    b report  keys sort   do     many times do       nh            h keys sort each do  k          nh k    h k        end     end   end end         user     system      total        real hash sort  0 400000   0 000000   0 400000    0 405588  keys sort  0 250000   0 010000   0 260000    0 260303    For big hashes difference will grow up to 10x and more

User · Answer

I ve always used sort by  You need to wrap the  sort by output with Hash   to make it output a hash  otherwise it outputs an array of arrays  Alternatively  to accomplish this you can run the  to h method on the array of tuples to convert them to a k  gt v structure  hash    hsh    a    gt  1000   b    gt  10   c    gt  200000  Hash hsh sort by  k v  v    or hsh sort by  k v  v  to h   There is a similar question in  How to sort a Ruby Hash by number value

User · Answer

Sort hash by key  return hash in Ruby   With destructuring and Hash sort  hash sort     ak       bk      ak  lt   gt  bk   to h   Enumerable sort by  hash sort by    k  v  k   to h   Hash sort with default behaviour   h      b    gt  2   c    gt  1   a    gt  3    h sort           e g    a   20   lt   gt    b   30  hash sort to h    gt     a    gt  3   b    gt  2   c    gt  1     Note   lt  Ruby 2 1  array      key    value     hash    Hash array  hash    gt    key   gt  value     Note    Ruby 2 1     key    value    to h    gt    key   gt  value

User · Answer

In Ruby 2 1 it is simple   h sort to h

User · Answer

ordered       unordered keys sort each do  key     ordered key     unordered key  end

User · Answer

ActiveSupport  OrderedHash is another option if you don t want to use ruby 1 9 2 or roll your own workarounds

User · Answer

I liked the solution in the earlier post   I made a mini-class  called it class AlphabeticalHash  It also has a method called ap  which accepts one argument  a Hash  as input  ap variable  Akin to pp  pp variable   But it will  try and  print in alphabetical list  its keys   Dunno if anyone else wants to use this  it s available as a gem  you can install it as such  gem install alphabetical hash  For me  this is simple enough  If others need more functionality  let me know  I ll include it into the gem   EDIT  Credit goes to Peter  who gave me the idea

User · Answer

You gave the best answer to yourself in the OP  Hash h sort  If you crave for more possibilities  here is in-place modification of the original hash to make it sorted   h keys sort each    k  h k    h delete k

User · Answer

Note  Ruby    1 9 2 has an order-preserving hash  the order keys are inserted will be the order they are enumerated   The below applies to older versions or to backward-compatible code   There is no concept of a sorted hash  So no  what you re doing isn t right   If you want it sorted for display  return a string         h sort map  k v     k inspect   gt   v inspect    join               or  if you want the keys in order   h keys sort   or  if you want to access the elements in order   h sort map do  key value      keys will arrive in order to this block  with their associated value  end   but in summary  it makes no sense to talk about a sorted hash  From the docs   The order in which you traverse a hash by either key or value may seem arbitrary  and will generally not be in the insertion order   So inserting keys in a specific order into the hash won t help

[ruby] Sort hash by key, return hash in Ruby

Examples related to ruby

Examples related to sorting

Examples related to hashmap