class - 定义类 : difference between var, val 并忽略它？

Question

以下三个 Scala 声明有什么区别？我了解general distinction between val and var .

class A(x: T){ ... }
class B(val x: T){ ... }
class C(var x: T){ ... }

Answer 1

A 和 B 之间的区别(val 和 var 都创建访问器):

class A(a: Int) {}

// Doesn't compile (value a is not a member of)
// (new A(1)).a

class B(val b: Int) {}

(new B(1)).b                                    //> res0: Int = 1