CODEWITHSUNDEEP
scala
prady
prady

Reputation: 593

How do I use conditional logic inside scala require method?

My Example : 

class ComplexNum(val real:Int,val imaginary:Int) {

  require((real==0 && imaginary==0 ),"Real or Imaginary, either any one should have value") 

}

what I am trying to achieve is commented as below,

object main extends App {
  val complexNumber1= new ComplexNum(1,1) //Should Not throw an error
  val complexNumber2= new ComplexNum(0,1) //Should Not throw an error
  val complexNumber3= new ComplexNum(1,0) //Should Not throw an error
  val complexNumber4= new ComplexNum(0,0) //Should throw an error
}

Currently I am getting error for first 3 conditions and no error for 4th condition.

Can someone please help me to understand the require method with above example with correct solution?

Upvotes: 0

Views: 318

Answers (2)

jwvh
jwvh

Reputation: 51271

A simple case of logic inversion.

require(!(real==0 && imaginary==0),"Real or Imaginary, either any one should have value")

... can also be expressed as ...

require(real!=0 || imaginary!=0,"Real or Imaginary, either any one should have value")

Upvotes: 1

Ramesh Maharjan
Ramesh Maharjan

Reputation: 41987

You have written require method as real and imaginary variables should always be 0. So if you pass any integer value other than 0 then you would have following error

java.lang.IllegalArgumentException: requirement failed: Real or Imaginary, either any one should have value

If you want Real or Imaginary, either any one should have value then you should define require method as

class ComplexNum(val real:Int,val imaginary:Int) {
  require((Option(real).isDefined && Option(imaginary).isDefined),"Real or Imaginary, either any one should have value")
}

Upvotes: 1

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