Scala中的重载Val [英] Overriding vals in Scala

问题描述

我试图这样在Scala中覆盖val:

I have tried to override val in Scala as this:

trait T{
  val str: String
}

sealed abstract class Test extends T{
  val str: String = "str"
}

class Test1 extends Test{
  val str = super.str + "test1" //super may not be used on value str
}

但是这个拒绝编译.为什么?我想使用抽象类的值本身覆盖抽象类中的值.该怎么做?

But this refused to compile. Why? I wanted to override value in the abstract class using the abstract class's value itself. How to do this?

在我的特殊情况下，我 不能将其作为类参数传递.

In my particular case I cannot pass it as a class parameter.

推荐答案

Scala编译器不允许在val上使用super.如果您不关心重新评估，则可以使用def代替.

Scala compiler does not allow to use super on a val. If you are not caring about re-evaluation, you can just use def instead.

trait T{
  def str: String
}

sealed abstract class Test extends T{
  def str: String = "str"
}

class Test1 extends Test{
  def str = super.str + "test1" //super may not be used on value str
}

defined trait T
defined class Test
defined class Test1

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