Question

Pardon me if it’s simple, but what is the most efficient way to do the following in scala:

Say I have two collections A and B with exactly same number of elements. For example,

A = {objectA1, objectA2, .... objectAN} 
B = {objectB1, objectB2, .... objectBN}

I would like to get {{objectA1, objectB1}, {objectA2, objectB2}, ... {objectAN, objectBN}}. Note that these collections might be very large.

Answer 1

Zip them:

A zip B

Example:

scala> val a = Seq(1, 2, 3, 4, 5)
a: Seq[Int] = List(1, 2, 3, 4, 5)

scala> val b = Seq('a', 'b', 'c', 'd', 'e')
b: Seq[Char] = List(a, b, c, d, e)

scala> a zip b
res5: Seq[(Int, Char)] = List((1,a), (2,b), (3,c), (4,d), (5,e))

If A and B are iterators, this will create an iterator of pairs as well.