<Illustrationcaption="Computer inputs"alt="Ones and zeroes."src="/images/docs/illustrations/i_inputs2.png"/>
</IllustrationBlock>
In both cases, **you must set [state variables](/learn/state-a-components-memory#anatomy-of-usestate) to update the UI.** For the form you're developing, you will need to change state in response to a few different inputs:
* **Changing the text input** (human) should switch it from the *Empty* state to the *Typing* state or back, depending on whether the text box is empty or not.