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 is 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.
如果@associated_linked_pub
是一个数组,请尝试
if @associated_linked_pub.include?(linkedpub.LPU_ID)
链接地址: http://www.djcxy.com/p/25680.html
上一篇: 有没有反过来的'会员?' 方法在红宝石?
下一篇: 我将如何检查是否在值数组中找到值