user3663882 user3663882 - 3 months ago 6
Scala Question

Using class parameters to assign field value

I'm new to scala and would like to use class parameters to assign the value to a field of the same. In Java, we do similar thing within a constructor:

public class Test{

private final int value;

public Test(int value){
this.value = value;
}
}


Now, I tried to do a similar thing in
Scala
:

class Test(value: Int){
val value = ..WHAT..value //Is there a way to assign a parameter value to a field with the same name?
}

object Test{
def testMethod = //access value and do something with it.
}


Can we do something similar to what we can in do in Java?

Answer

Scala provides a shorter syntax for creating such a member - just add the keyword val before the argument name in the class parameter list. You can also add a modifier (e.g. private):

scala> :paste
// Entering paste mode (ctrl-D to finish)

class Test(private val value: Int)

object Test {
  def testMethod(t: Test) = t.value
}

// Exiting paste mode, now interpreting.

defined class Test
defined module Test

scala> Test.testMethod(new Test(5))
res1: Int = 5