Use pluck instead of collect in ruby on rails.

I have seen lot of people use collect in ruby on rails. For example:

  User.first.gifts.collect(&:id)# Bad smell.

Use pluck in case you just want to get id ie:

  User.first.gifts.pluck(:id)

Explanation

‘pluck’ is on the DB level. It will only query the particular field. See this.

When you do:

  User.first.gifts.collect(&:id)

You have objects with all fields loaded and you simply get the ‘id’ thanks to the method based on Enumerable.

So:

• if you only need the ‘id’, use ‘pluck’
• if you need all fields, use ‘collect’
• if you need some fields, use ‘select’ and ‘collect’

So keep in mind when to use pluck instead of collect in ruby on rails.