how to form an array from list of objects

Question

I know little about ruby, my following implementation works, but I really feel the approach curbsome

@surfaces = []
Surface.all.each do |surface|
    @surfaces << surface.name
end

the purpose is to extract name value of each surface objects and form them into an array, can anyone tell me the smart way to do this? thanks

Answer 1

You can use Surface.all.collect(&:name).

EDIT: this is equivelent to doing something like this:

Surface.all.collect do |s|
  s.name
end

Answer 2

Use Enumerable#map to turn one enumerable into another enumerable with a 1-to-1 mapping of elements. Combine with Symbol#to_proc when the mapping involves simply invoking a single method on each element of the input enumerable.

Both of these are equivalent:

@surfaces = Surface.all.map(&:name)

@surfaces = Surface.all.map do |surface|
  surface.name
end

Answer 3

FYI, collect and map alias to the same internal pattern in Ruby.

Here's the stackflow reference: Difference between map and collect in Ruby?