How to create an array with help of a loop

Question

I have a model Image:

class Image < ActiveRecord::Base
  attr_accessible :date, :description, :name, :quality, :size
end

I now have an instance variable with a bunch of images:

@images = Image.where("id<30")

I want to create a @keywords variable with all the names of the images. In the Rails console I can do:

for i in [email protected]
  puts @image[i].name
end

and I get a list of all the name of the images.

How can I define the @keywords variable in my images_controller in order to store this list in an array?

@keywords = ...?

The output should be a list, preferrably comma seperated, with the image names:

"Blue ocean, Green leafs, Sunset in New York"

Baldrick · Accepted Answer · 2012-12-03 15:25:05Z

4

@keywords = @images.collect{|i| i.name}.join(",")

This will get an array of all the names and join them into a comma-separated string.

edited Dec 3, 2012 at 15:25

Baldrick

24.4k6 gold badges76 silver badges80 bronze badges

answered Dec 3, 2012 at 15:21

Scott S

2,73618 silver badges21 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

mdesantis Over a year ago

shorter: @images.map(&:name).join(',') :-)

the Tin Man Over a year ago

shorter: @images.map(&:name) * ',' if we're playing that game.

user929062 Over a year ago

Is this just "nice" to change it to the short version or is this also a performance issue, means the query will take less time?

Scott S Over a year ago

This is mostly syntactic sugar - according to the docs, #map is an alias of collect and #* with a string is the same as join. Whether or not the &:name syntax is any faster than the block I provided, I'm not sure.

Collectives™ on Stack Overflow

How to create an array with help of a loop

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related