如何测试 class 实例是否是它扩展的 class 的实例？

Question

class A
class B extends A

b = new B
b instanceof B # true
b instanceof A # false

如何检查 b 是 A 的 "also" 实例（因为 B 扩展了 A）

Answer 1

class A
class B extends A

b = new B
console.log "b is an instance of extended class " if b instanceof B # b is an instance of extended class 
console.log "b is an instance of extended class A because B extends a " if b instanceof A # b is an instance of extended class A because B extends a

您可以简单地使用：

if b instanceof B && b instanceof A  #B is instance of A and B classes
  console.log "B is instance of A and B classes"

这是代码片段： http://repl.it/meN/1

如何测试 class 实例是否是它扩展的 class 的实例？

How to test if class instance is instance of class that it extends?

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