案例类相等性仅基于其主要构造函数属性,无论它们是var
or val
(是的,你可以让它们var
通过给出明确的var
覆盖隐含的val
该案例类构造函数参数拥有。)在 a 的主体中添加属性case class
does not影响编译器生成的equals(other: Any)
method.
Witness:
package rrs.scribble
object CCVarEq
{
case class CC1(i: Int, j: Float, var k: Double)
case class CC2(i: Int, j: Float, var k: Double) {
var l = math.Pi
}
def show {
val cc11 = CC1(1, 2.0f, 3.0)
val cc12 = CC1(1, 2.0f, 3.0)
val cc21 = CC2(1, 2.0f, 3.0); cc21.l = math.E
val cc22 = CC2(1, 2.0f, 3.0)
printf("cc11 == cc12: %s%n", cc11 == cc12); cc12.k = math.Pi * math.E
printf("cc11 == cc12: %s%n", cc11 == cc12)
printf("cc21 == cc22: %s%n", cc21 == cc22)
}
}
在 REPL 中:
scala> import rrs.scribble.CCVarEq._
import rrs.scribble.CCVarEq._
scala> show
cc11 == cc12: true
cc11 == cc12: false
cc21 == cc22: true
jamie 关于并发的所有观点也都是有效的。