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JavaScript REST APIs with Express Getting to Know REST APIs GET a Quote, GET all Quotes

Posted by korovyef
korovyef
7,056 Points

Async callback and the data declaration

Hi, I am a bit confused. The const data variable gets declared after the app.get() method is called. Because the const keyword is used it won't get hoisted. Is this possible because the callback function gets placed on the call stack and will be executed after the data variable is already assigned?

1 Answer

Steven Parker
Steven Parker
231,236 Points
Steven Parker
Steven Parker
231,236 Points

The "app.get" call registers the request handler but it does not invoke it. So what's important is that "data" gets defined before a request is handled.

To be absolutely certain of this, it might have been a good idea to define "data" before calling "listen", but it wasn't at all possible back when "app.get" was called.