ruby add to array... simple question

Question

I'm sure this is simple but I can't seem to get it:

Works:

@build1 = Booking.build_booking('2009-06-13',3,2,18314)
@build2 = Booking.build_booking('2009-06-13',3,4,18317)
@build = @build1 + @build2

What I want to work...

#for item in @cart.items do
#  @build << Booking.build_booking('2009-06-13',3,2,18314)
#end

Doesn't work either...

#(1..3).each do |i|
#  @build << Booking.build_booking('2009-06-13',3,2,18314)
#end

Answer 1

@build will need to be an array, or an object that responds to <<, for @build << to work.

When you've done:

@build = @build1 + @build2

What is the value of @build?

Answer 2

For the two iterating examples you'd need to set @build prior to calling << on it.

I'm not sure what build_booking is returning but if it's an array (I'm guessing from the first, working, example) then you'd probably want to add the result of build_booking to @build. E.g.

@build = []
for item in @cart.items do
  @build += Booking.build_booking('2009-06-13',3,2,18314)
end

Answer 3

@build = []
for item in @cart.items do
  @build += Booking.build_booking('2009-06-13',3,2,18314)
end


 @build.flatten!

flatten will will work even Booking.build_booking is returning an array of bookings

Answer 4

I prefer using the wonderful array-methods that ruby has to offer over a for loop:

@build = @cart.items.map { |item| Booking.build_booking('2009-06-13',3,2,18314) }

Answer 5

The quick approach, though, would be to simply declare the array to combine the two elements:

@build = [ @build1, @build2 ]

I'd use an approach like Magnar, though, which is much more concise.