Play dead prototype chain

JavaScript You must be familiar with our prototype chain , When accessing properties that the object itself does not have ,js The engine will find whether the attribute exists in the prototype through the prototype chain .

If we replace the prototype in the prototype chain with a Proxy What will happen? ？

The engine will call Proxy Medium get Method , here Proxy It's just the object represented , and get What happens if this object is referenced in the method ？ It's a cycle , Soon the stack overflowed . In this case, the compiler cannot predict that the program will loop . The famous Godel's incomplete theorem also tells us , If you want to write a program, you can judge whether any program will terminate （ There is no dead cycle ） It's impossible .