useCallback

What is useCallback()?

The useCallback() Hook can be used to optimize the performance of an application. It receives a function and then creates a unique identity of that function, which will remain active until the dependencies of the Hook itself change.

This is important becasue we need to provide the same reference to a function when:

1. Dealing with PureComponents.
2. Functions implement their own shouldComponentUpdate() method.
3. Functions are wrapped by React.memo().

The useCallback() Hook expects two parameters. The first is a function and the second is a ...