Scala - mutable (var) method parameter reference

Question

EDIT: I keep getting upvotes here. Just for the record, I no longer think this is important. I haven't needed it since I posted it.

I would like to do following in Scala ...

def save(srcPath: String, destPath: String) {     if (!destPath.endsWith('/'))         destPath += '/'     // do something } 

... but I can't beacuse destPath is a val. Is there any way to declare destPath as var?

Note: there are similar questions but in all of them OP just wanted to modify array.

Please do not advise following:

Mutating the input parameters is often seen as bad style and makes it harder to reason about code.

I think it's valid in imperative programming (Scala allows both, right?) and adding something like tmpDestPath would just add clutter.

EDIT: Don't misunderstand. I know that strings aren't mutable and I don't want a reference to reference because I don't want to modify data of caller. I just want to modify local reference to string that caller gave me with my string (eg. orig + '/'). I want to modify that value only in scope of current method. Look, this is perfectly valid in Java:

void printPlusOne(int i) {     i++;     System.out.println("i is: " + i);     System.out.println("and now it's same: " + i); } 

I don't have to create new variable and i don't have to compute i+1 twice.

Answer 1

You can't.

You'll have to declare an extra var (or use a more functional style :-)).

Simplistic example:

def save(srcPath: String, destPath: String) {     val normalizedDestPath =       if (destPath.endsWith('/')) destPath       else destPath + '/'     // do something with normalizedDestPath  }