Question

我的例子：

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
}

我想要达到的目的如下所述，

x = 10
rm(x) # removed x from the environment

x = 10
x %>% rm() # Doesn't remove the variable x

目前我收到前3个条件的错误，第4个条件没有错误。

有人可以帮我理解上面例子中的require方法和正确的解决方案吗？

Answer 1

您已将require方法写为real且imaginary变量应始终为0. 因此，如果您传递0以外的任何整数值，则会出现以下错误< / strong>

java.lang.IllegalArgumentException：要求失败：Real或Imaginary，任何一个都应该有值


如果您需要Real or Imaginary, either any one should have value，则应将require方法定义为

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

Answer 2

逻辑反演的一个简单例子。

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

...也可以表示为......

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

如何在scala require方法中使用条件逻辑？

2 个答案: