ruby - Find Value in Array of ActiveRecord Objects vs. Find Value from Repeated DB Calls -

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i return true, if array of contact(s) (model) contains contact id equal value. example:

@contacts = contact.all  @someval = "alskjdf"  find_val(@contacts, @someval)  def find_val(contacts, val)   @contact.each |c|     if c.id == val       return true     end   end   return false end

i have repeatedly in app (at 100 times particular actions), in order exclude data external api has list of contacts. going expensive?

i thought might able faster, similar activerecord find on array after it's been pulled down db, can't figure out. expensive call activerecord this?

contacts.find_by_id(@someval)

the above line have called hundreds of times... figure iterating through array less expensive. thanks!

the best approach index contacts in hash, using contact id key after retrieve them db:

contacts = contact.all.inject({}) {|hash, contact| hash[contact.id] = contact; hash }

then can contact contact[id] in performant way.


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