Frontend & browser·State, data and re-rendering
the field's value comes from state and every keystroke goes through your change handler before it appears.
Controlled input
Also calledcontrolled component
A form element whose displayed value is driven entirely by application state, with the DOM holding no independent copy. It makes validation, formatting and cross-field logic straightforward because there is exactly one value. The price is a re-render per keystroke and the classic trap of setting `value` without an `onChange`, which produces a field that cannot be typed into.