javascript - 读取外部类的阴影私有(private)字段

Question

我希望在类(class)内B我可以读取私有(private)字段 #a和 #x类(class)A .但实际上我只能读取#a , 万一访问 #x我收到一个错误:

Cannot read private member #x from an object whose class did not declare it

好像#x类(class)B A的阴影相似场.首先，这似乎不合逻辑 - 为什么它会以这种方式工作，如果它是故意的，那么它是以这种方式计划的吗？是否可以阅读 #x在 A实例在 B 内?

class A {
  #a = "A#a"
  #x = "A#x"

  static B = class B {
    #b = "B#b"
    #x = "B#x"

    static doSmth(obj) {
      try { console.log(obj.#a) } catch (e) { console.log(e.message) }
      try { console.log(obj.#b) } catch (e) { console.log(e.message) }
      try { console.log(obj.#x) } catch (e) { console.log(e.message) }
    }
  }
}

console.log("=== A ===")
A.B.doSmth(new A)
console.log("")
console.log("=== B ===")
A.B.doSmth(new A.B)

.as-console-wrapper.as-console-wrapper { max-height: 100vh }
.as-console-row.as-console-row:after { content: none }

如果重要的话，我正在使用 Google Chrome 89.0.4389.90。
PS:Same question in Russian.

Answer 1

赠送一部分来自 here

Like their public equivalent, private static methods are called on the class itself, not instances of the class. Like private static fields, they are only accessible from inside the class declaration.

您通过 一个 进入 乙方法论

A.B.doSmth(new A)

A#a
Cannot read private member #b from an object whose class did not declare it
Cannot read private member #x from an object whose class did not declare it

方法无权访问 A#x，因为 B#x 也声明了，而 A 无权访问它。
接下来你通过乙进入 乙方法论

A.B.doSmth(new A.B)

Cannot read private member #a from an object whose class did not declare it
B#b
B#x

方法 B 无法访问 A#а

class A {
  #a = "A#a"
  #b = "A#b"
  #x = "A#x"
  
  static doSmthA(obj) {
      try { console.log(obj.#a) } catch (e) { console.log(e.message) }
      try { console.log(obj.#b) } catch (e) { console.log(e.message) }
      try { console.log(obj.#x) } catch (e) { console.log(e.message) }
  }

  static B = class B {
    
    #a = "B#a"
    #b = "B#b"
    #x = "B#x"

    static doSmthB(obj) {
      try { console.log(obj.#a) } catch (e) { console.log(e.message) }
      try { console.log(obj.#b) } catch (e) { console.log(e.message) }
      try { console.log(obj.#x) } catch (e) { console.log(e.message) }
    }
  }
}

console.log("=== A ===")
A.doSmthA(new A)
console.log("")
console.log("=== B ===")
A.B.doSmthB(new A.B)

console.log("=== NEXT ===")

console.log("=== A ===")
A.doSmthA(new A.B)
console.log("")
console.log("=== B ===")
A.B.doSmthB(new A)