Scala constructor overloading parameter is not taking effect - scala

Question

I'm trying to understand what's wrong with the way I'm implementing constructor overloading. I want to add a constructor that accepts an argument count, in a class that has a member with the same name.
The idea is to have count calculated off of one of the default constructor parameters, unless it is passed through the overload constructor. I show the code later.
To convince myself this can work, I constructed a quick and simple test:
import org.scalatest.FunSuite
class ConstructorOverloadTest extends FunSuite {
test("Overload parameter shadows class member") {
val actual = new TestME(200).length
200 === actual
1 !== actual
}
class TestME(name:String) {
val length = name.length
def this(length:Int) = {
this("*")
}
}
}
The test passes as expected. Which leads me to understand that the overload constructor parameter length shadows/replaces the class member length.
But when I do the same in another class, the class member is not shadowed/replaced.
class MyClass(input1: Array[Float], input2: Array[Byte], input3: Array[Float]) {
val count = input2.length
val index = doSomething()
def this(count: Int) = {
this(Array(), Array(), Array())
}
def printCount() = {
if (this.count == 0)
println("ZERO")
else
println("OTHER")
}
}
When I use this class as follows
val myInstance = new MyClass(200)
myInstance.printCount()
I expect it to print OTHER to the screen. Instead, it prints ZERO.
Why?

Answer 1

There appears to be something wrong with your test. new TestME(200).length returns 1, indicating that the constructor param does not in fact override length.
class TestME(name:String) {
val length = name.length
def this(length:Int) = {
this("*")
}
}
println(new TestME(200).length)
1
Per summerbulb's comments:
The test's assertions should be wrapped in assert:
// Closer to correct...
assert(200 === actual)
assert(1 !== actual)
Actual and expected values should be passed in that order:
// Correct!
assert(actual === 200)
assert(actual !== 1)