How can i add an item using loop in ListBuffer of tuples using Scala? I have declared the List as:
val listV = new ListBuffer[(String,Int)]();
On adding item like this:
listV += ("a",1)
gives an error of : type mismatch as following
[error] found : String("a")
[error] required: (String, Int)
[error] listV += ("a",1)
[error] ^
[error] one error found
Any suggestions to resolve this ? Thanks in anticipation
+= is a method on ListBuffer, so the scala compiler thinks you're trying to pass two parameters to the += method. You need an extra set of parenthesis to emphasize that the tuple is a single element and not an invalid parameter list.
listV += (("a", 1))
More parentheses. ("a",1) is interpreted as adding a String and an Int to listV.
scala> val listV = new ListBuffer[(String, Int)]
listV: scala.collection.mutable.ListBuffer[(String, Int)] = ListBuffer()
scala> listV += (("a", 1))
res0: listV.type = ListBuffer((a,1))
You can use this syntax which compiler can mix up with the function call:
listV += "a" -> 1
If you are more used to always having braces around Tuples this will also be interpreted correctly
listV += ("a" -> 1)
