This is a comprehensive coverage of what Callback is. It is worth spending a couple of days working and replicating the examples here.
A callback function, also known as a higher-order function, is a function that is passed to another function (let’s call this other function “otherFunction”) as a parameter, and the callback function is called (or executed) inside the otherFunction. A callback function is essentially a pattern (an established solution to a common problem), and therefore, the use of a callback function is also known as a callback pattern.
... you should look at your own code for opportunities to use callback functions, for they will allow you to:
- Do not repeat code (DRY—Do Not Repeat Yourself)
- Implement better abstraction where you can have more generic functions that are versatile (can handle all sorts of functionalities)
- Have better maintainability
- Have more readable code
- Have more specialized functions.