Update hook descriptions

snippets/useComponentWillUnmount.md

@@ -3,16 +3,20 @@ title: useComponentWillUnmount
 tags: hooks,effect,beginner
 ---
 
-A hook that executes a callback immediately before a component is unmounted and destroyed.
+Executes a callback immediately before a component is unmounted and destroyed.
 
-- Use `React.useEffect()` with an empty array as the second argument and return the provided callback to be executed only once before cleanup.
+- Use `useEffect()` with an empty array as the second argument and return the provided callback to be executed only once before cleanup.
+- Behaves like the `componentWillUnmount()` lifecycle method of class components.
 
 ```jsx
 const useComponentWillUnmount = onUnmountHandler => {
-  React.useEffect(() => () => {
-    onUnmountHandler()
-  }, []);
-}
+  React.useEffect(
+    () => () => {
+      onUnmountHandler();
+    },
+    []
+  );
+};
 ```
 
 ```jsx
@@ -20,7 +24,7 @@ const Unmounter = () => {
   useComponentWillUnmount(() => console.log('Component will unmount'));
 
   return <div>Check the console!</div>;
-}
+};
 
 ReactDOM.render(<Unmounter />, document.getElementById('root'));
 ```