CODEWITHSUNDEEP
scala
user1592470
user1592470

Reputation: 401

How can I loop though a set and reassign every item in collection with new value?

Hi I want to loop a set of Strings and convert them from String type to ObjectId type.

I tried this way:

followingIds.foreach(e => e = new ObjectId(e))

But I cant do that assignement.

I also tried using "for" but I don't know how to access each position of the Set by Index.

for (i <- 0 until following.size) {
   following[i] = new ObjectId(following[i])
}

This neither work,

Can anyone help me?!? Please!

Upvotes: 3

Views: 3158

Answers (2)

idonnie
idonnie

Reputation: 1713

Java-1.4-like?

val mutableSet: collection.mutable.Set[AnyRef] = collection.mutable.Set[AnyRef]("0", "1", "10", "11")
//mutableSet: scala.collection.mutable.Set[AnyRef] = Set(0, 1, 10, 11)

for (el <- mutableSet) el match { 
  case s: String  => 
    mutableSet += ObjectId(s)
    mutableSet -= s
    s
  case s => s
}

mutableSet
//res24: scala.collection.mutable.Set[AnyRef] = Set(ObjectId(0), ObjectId(11), ObjectId(10), ObjectId(1))

Upvotes: 0

om-nom-nom
om-nom-nom

Reputation: 62835

If you insist on mutability you can go with something like this: 

var followingIds = Set("foo", "bar")
followingIds = followingIds.map(e => new ObjectId(e))

But you can make your code more scalish with immutable things: 

val followingIds = Set("foo", "bar")
val objectIds = followingIds.map(e => new ObjectId(e))

Now variables (values) names are pretty descriptive

Upvotes: 12

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