scala build up string from iterating over map

Question

if i have a map and want to build up a string from iterating over it, is there a way to have the final string be a result of an expression instead of defining a variable and modifying that inside a loop?

instead of this

val myMap = Map("1" -> "2", "3"->"4") 
var s = ""
myMap foreach s += ...

i'd rather it be

var s = myMap something ...

Answer 1

I'd just map and mkString. For example:

val s = (
    Map("1" -> "2", "3"->"4") 
    map { case (key, value) => "Key: %s\nValue: %s" format (key, value) } 
    mkString ("", "\n", "\n")
)