Tell don’t ask

Dennis Zelada
Aug 8, 2017 · 1 min read

Instead of asking the internal state of an object just let it to decide what to do with the message.

Pros:

  • The data and the methods are together on the same place.
  • It’s easier to change everything because they are together.
  • Remove conditionals.

Cons:

  • Add additional responsability.

When not to follow this principle:

  • Most of the cases adding more responsability to an Active record instance is not a good idea, so this is a case when you don’t want to follow tell don’t ask.
Dennis Zelada

Written by

Things that I would have liked to know before