Scala collection map var to another value

Question

I have a collection col with elements of type Foo.

Foo has a var bar, which I need to change for every element in the collection.

Currently my code looks like this

col.map(baz => {
  baz.bar = 
  baz
})

Is there a nicer way to do this? I feel like this could be done with a one liner.

user_5205022 · Answer

foreach is designed for side-effects like that

col.foreach(_.bar = )

after this col will have all elements mutated. If you wish to avoid Unit return type try chaining

import util.chaining._
col.map(_.tap(_.bar = ))

or other way around

col.tap(_.foreach(_.bar = ))

Idimoatic approach would be to avoid var and have immutable case class Foo then copy

col.map(_.copy(bar = ))