Coffeescript 如何测试类实例是否是它扩展的类的实例？

如何检查

b

是否也是

A

的实例（因为

b

扩展了

A

）

您可以简单地使用：

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

以下是代码snipt：

---

我不明白你的问题，

b A的instanceof A

返回

true

。

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

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"