Select all correct statements about val form and def form definitions:
Get an explanation when it's available:
  • Function parameters can be passed by value or be passed by name.
    The same distinction applies to definitions.
    The def form is “by-name”, its right hand side is evaluated on each use.
    There is also a val form, which is “by-value”.
    val x = 2
    val y = square(x)
    The right-hand side of a val definition is evaluated at the point of the definition itself.
    Afterwards, the name refers to the value. For instance, y above refers to 4, not square(2).
  • The difference between val and def becomes apparent when the right hand side does not terminate.
    def loop: Boolean = loop
    A definition
    def x = loop
    is OK, but a definition
    val x = loop
    will lead to an infinite loop.

Следи за CodeGalaxy

Мобильное приложение Beta

Get it on Google Play
Обратная Связь
Продолжайте изучать
тесты по Scala
Зарегистрируйся сейчас
или Подпишись на будущие тесты