How do you sort an array alphabetically using sort_by in ruby?

Question

I have an array of memberships. In each membership is a group. I need to sort this array of memberships by the name of the group. I've tried a bunch of different ways, and the latest way is this:

@memberships.sort_by! { |m| m.group.name }

However, this doesn't sort by the name. It appears to be randomly sorting the array.

• Membership belongs_to :group
• Group has_many :memberships

@memberships is equal to:

[
  {
  id: 2141,
  user_id: 491,
  group_id: 271,
  member_type: "member",
    group: {
      id: 271,
      name: "Derek's",
      privacy: "open",
      bio_image_url: "/bio_images/medium/missing.png?1340285189",
      member_count: 1,
      upcoming_checkins_count: 0
    }
  },
  {
  id: 2201,
  user_id: 221,
  group_id: 291,
  member_type: "member",
    group: {
      id: 291,
      name: "Rounded Developement",
      privacy: "closed",
      bio_image_url: "/groups/medium/291/bioimage.jpg?1340736175",
      member_count: 7,
      upcoming_checkins_count: 0
   }
}
]

NOTE: This does work --> @memberships.sort_by! { |m| m.group.id }

It will order the array based on the group.id so maybe it has something to do with sorting alphabetically?

Any help would be much appreciated.

Answer 1

Wow, after struggling with this for an extremely long time, I realized my problem was a simple one. I was sorting by group.name but some of the group names were uppercase and some were lower, which was throwing it all off. Converting everything to downcase worked well.

@memberships.sort_by!{ |m| m.group.name.downcase }

Answer 2

排序方法是一种选择吗？

ary.sort{ |a,b| a[:group][:name] <=> b[:group][:name] }

Answer 3

I don't see how your code is working. I can't access the hashes in the arrays using m.group.name

Here's a working syntax

@memberships.sort_by!{ |m| m[:group][:name] }