There are many situations where you want to programmatically control the value of a form field. Maybe you want to set the value of one field based on the user’s interactions with another element. Or maybe you want to change the user’s input as they’re typing it. In this example, we’ll be preventing the user from typing upper case characters into our field by turning our input from an “Uncontrolled field” to a “Controlled field.”
You can learn more about Controlled fields and components from the React documentation.