Scala 趣题 3

会输出什么？

trait A {
  val audience: String
  println("Hello "+ audience)
}

class BMember(a: String = "World") extends A {
  val audience = a
  println("I repeat: Hello " + audience)
}

class BConstructor(val audience: String = "World") extends A {
  println("I repeat: Hello " + audience)
}

new BMember("Readers")
new BConstructor("Readers")

解释：

When instantiating superclasses or traits, the parent constructor
can be visualized as being executed before the first line of the child
constructor but after the class definition.

class definition的意思就是class的声明（就是{ 之前的部分）

时间： 2024-11-05 13:30:30

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