How to simplify this 'for' loop?

Question

val xsa = List(1,2,3)
val xsb = List(1,2,3)
for (i <- 0 until xsa.size) {
    val a = xsa(i)
    val b = xsb(i)
    println(a + "_" + b)
}

I want to simplify the length equals' List or Array. I hoped to do it like this:

for (a <- xsa; b <- xsb)
    println(a + "_" + b)

But why does it only iterate xsb once?

score 19 · Accepted Answer · answered Dec 28 '10 at 14:35

19

for ((a,b) <- xsa zip xsb)
  println(a + "_" + b)

answered Dec 28 '10 at 14:35

Debilski

score 8 · Answer 2 · answered Dec 28 '10 at 15:10

8

(xsa, xsb).zipped foreach ((a, b) => println (a + "_" + b))

Or

(xsa, xsb).zipped map (_ + "_" + _) foreach println

answered Dec 28 '10 at 15:10

Landei

score 1 · Answer 3 · answered Dec 28 '10 at 14:38

1

val x = xsa.zip(xsb)
for ((a, b) <- x)
    println(a + "_" + b)

answered Dec 28 '10 at 14:38

sblundy

3 Answers3