Developing Node.js Applications on IBM Cloud

Understanding asynchronous callback

This chapter discusses two important concepts: Asynchronous method invocation and callbacks:

•Asynchronous method invocation

This is a design pattern where an invoker method does not block while waiting for the invoked method to finish processing and return a result. Instead, the invoked method is run in a separate thread and the invoker is notified when the result is ready.

•Callback function

This is a function that is passed to another function as a parameter and the callback function is called and run within ...