How would I check if a value is found in an array of values
I want to perform an if condition where, if linkedpub.LPU_ID
is found in an array of values(@associated_linked_pub
), do some action.
I tried the following but the syntax is not correct.
Any suggestion i开发者_如何转开发s most welcomed..Thanks a lot
<% for linkedpub in Linkedpub.find(:all) %>
<% if linkedpub.LPU_ID IN @associated_linked_pub %>
# do action
<%end%>
<%end%>
You can use Array#include?
So...
if @associated_linked_pub.include? linkedpub.LPU_ID
...
Edit:
If @associated_linked_pub
is a list of ActiveRecord objects then try this instead:
if @associated_linked_pub.map{|a| a.id}.include? linkedpub.LPU_ID
...
Edit:
Looking at your question in more detail, it looks like what you are doing is VERY inefficient and unscalable. Instead you could do...
For Rails 3.0:
Linkedpub.where(:id => @associated_linked_pub)
For Rails 2.x:
LinkedPub.find(:all, :conditions => { :id => @associated_linked_pub })
Rails will automatically create a SQL IN query such as:
SELECT * FROM linkedpubs WHERE id IN (34, 6, 2, 67, 8)
linkedpub.LPU_ID.in?(@associated_linked_pub.collect(&:id))
Using in?
in these cases has always felt more natural to me.
if @associated_linked_pub
is an array, try
if @associated_linked_pub.include?(linkedpub.LPU_ID)
@associated_linked_pub.collect(&:id).include?(linkedpub.LPU_ID)
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