Hi Everyone,
I have started learning scala and am working on a task and facing some problem:
Following is what I have worked on. But I am not getting a desired output but an error. " class Variables need to be abstract since it has two unimplemented variables"
Need your Help. Thanks in Advance.
trait ArithmeticOperations {
var x :Int
var y: Int
def add
def subtract
def multiply
def divide
}
class Variables (xc:Int, yc:Int) extends ArithmeticOperations {
x= xc
y= yc
def add() = x + y
def subtract() = x - y
def multiply() = x * y
def divide() = x / y
}
object TraitExample extends App{
val input1 = args(0).toInt
val input2 = args(1).toInt
var variable = new Variables(input1, input2)
println(variable.add())
println(variable.subtract())
println(variable.multiply())
println(variable.divide())
}
Output:
Execute the program to print the outputs:
(Traits.scala is a file name)
scala Traits.scala 5 3
Output will be:
8
2
15
1
I made a mistake not to initialize the x and y variable. I have corrected that but still I am not getting the desired output.
I am getting
()
()
()
()
with the call I have made in the code.
You didn’t declare the return types of the defs in your trait, so they default to type Unit. (Which always prints as ().)
2 Likes
Greetings dear professional Colleagues,
Please, I am very new in Scala. I want to learn from you how I can set eclipse environment to be scala EDI.
Your help is much appreciated.
Folakemi
You’re looking for the Scala IDE. But note that not an awful lot of people are using it nowadays – most folks are currently using IntelliJ.
1 Like
Thanks for your response. It work 
Should we write code as
trait ArithmeticOperations {
var x :Int
var y: Int
def add
def subtract
def multiply
def divide
}
class Variables defs (xc:Int, yc:Int) extends ArithmeticOperations {
x= xc
y= yc
def add() = x + y
def subtract() = x - y
def multiply() = x * y
def divide() = x / y
}
object TraitExample extends App{
val input1 = args(0).toInt
val input2 = args(1).toInt
var variable = new Variables(input1, input2)
println(variable.add())
println(variable.subtract())
println(variable.multiply())
println(variable.divide())
}
Please correct my mistake
written required code as
trait ArithmeticOperations {
val x :Int
val y: Int
def add
def subtract
def multiply
def divide
}
class Variables (xc: Int, yc: Int) extends ArithmeticOperations {
val x= xc
val y= yc
def add() = x + y
def subtract() = x - y
def multiply() = x * y
def divide() = x / y
}
object TraitExample extends App{
val input1 = args(0).toInt
val input2 = args(1).toInt
var variable = new Variables(input1, input2)
println(variable.add())
println(variable.subtract())
println(variable.multiply())
println(variable.divide())
}
Output getting as
$ scala TraitExample 5 3
()
()
()
()
It should be
$ scala TraitExample 5 3
8
2
15
1
Please help
Finally succeed code will be
trait ArithmeticOperations {
val x :Int
val y: Int
def add: Int
def subtract: Int
def multiply: Int
def divide: Int
}
class Variables (xc: Int, yc: Int) extends ArithmeticOperations {
val x= xc
val y= yc
def add() = x + y
def subtract() = x - y
def multiply() = x * y
def divide() = x / y
}
object TraitExample extends App{
val input1 = args(0).toInt
val input2 = args(1).toInt
var variable = new Variables(input1, input2)
println(variable.add())
println(variable.subtract())
println(variable.multiply())
println(variable.divide())
}
working as expected result
1 Like