Tweak

beta/src/pages/apis/usestate.md

@@ -795,7 +795,9 @@ In most cases you don't need derived state:
 * If you want to reset the entire component tree's state, [pass a different `key` to your component.](#resetting-state-with-a-key)
 * If you can, update all the relevant state in the event handlers.
 
-Let's consider an example. This `CountLabel` component displays the `count` prop passed to it:
+If none of this applies and you still need to adjust some state based on a prop, try derived state.
+
+Here's an example. This `CountLabel` component displays the `count` prop passed to it:
 
 ```js CountLabel.js
 export default function CountLabel({ count }) {
@@ -803,7 +805,7 @@ export default function CountLabel({ count }) {
 }
 ```
 
-You want to show whether the counter has *increased or decreased* since the last change. The `count` prop doesn't tell you this -- you need to keep track of its previous value. Add the `prevCount` state variable to track it. Add another state variable called `trend` to hold whether the count has increased or decreased. Compare `prevCount` with `count`, and if they're not equal, update both `prevCount` and `trend`. Now you can show both the current count prop and *how it has changed since the last render*. Here, `trend` is an example of derived state:
+Say you want to show whether the counter has *increased or decreased* since the last change. The `count` prop doesn't tell you this -- you need to keep track of its previous value. Add the `prevCount` state variable to track it. Add another state variable called `trend` to hold whether the count has increased or decreased. Compare `prevCount` with `count`, and if they're not equal, update both `prevCount` and `trend`. Now you can show both the current count prop and *how it has changed since the last render*. Here, `trend` is an example of derived state:
 
 <Sandpack>
 
@@ -852,4 +854,6 @@ button { margin-bottom: 10px; }
 
 </Sandpack>
 
+In this example, if you can't modify the parent component to track it, derived state is the right solution.
+
 When you can, try to avoid derived state. However, derived state is better than updating state in an effect. This is because calling the `set` function in render restarts a render immediately without waiting for child components.