diff --git a/16-buttons/a-simple-button/src/App.js b/16-buttons/a-simple-button/src/App.js
index 7a3aac4..f671ca5 100644
--- a/16-buttons/a-simple-button/src/App.js
+++ b/16-buttons/a-simple-button/src/App.js
@@ -1,19 +1,19 @@
 import React, { Component } from 'react';
+import Button from './Button';
 import './App.css';
 
 class App extends Component {
   render () {
     return (
       <div className="top-toolbar">
-        <button onClick={this.handleAddUser}>Add User</button>
+        <Button onClick={this.handleAddUser}>Add User</Button>
       </div>
     );
   }
   handleAddUser = () => {
     // handle button click
     console.log('add user');
-  }
+  };
 }
 
 export default App;
-
diff --git a/16-buttons/a-simple-button/src/Button.js b/16-buttons/a-simple-button/src/Button.js
new file mode 100644
index 0000000..adddabd
--- /dev/null
+++ b/16-buttons/a-simple-button/src/Button.js
@@ -0,0 +1,3 @@
+import React from 'react';
+
+export default props => <button onClick={props.onClick}>Add User</button>;
diff --git a/16-buttons/d-segmented-button/src/SegmentedButton.js b/16-buttons/d-segmented-button/src/SegmentedButton.js
index 082f8b9..acc63d0 100644
--- a/16-buttons/d-segmented-button/src/SegmentedButton.js
+++ b/16-buttons/d-segmented-button/src/SegmentedButton.js
@@ -46,21 +46,23 @@ class SegmentedButton extends Component {
     const { allowDepress } = this.props;
     const { target: btn } = e;
     const { tagName } = btn;
-    let { pressed } = this.state;
+    let pressedState = this.state.pressed.slice(0);
     
     if (tagName === 'BUTTON') {
       const { value } = btn;
-      const valIndex = pressed.indexOf(value);
+      const valIndex = pressedState.indexOf(value);
       const isPressed = valIndex !== -1;
       // toggle the "pressed" button state
       if (isPressed) {
-        if (allowDepress || (!allowDepress && pressed.length > 1)) {
-          pressed = pressed.filter(item => item !== value);
+        if (allowDepress || (!allowDepress && pressedState.length > 1)) {
+          pressedState = pressedState.filter(item => item !== value);
         }
       } else {
-        pressed = [...pressed, value];
+        pressedState = [...pressedState, value];
       }
-      this.setState({ pressed });
+      this.setState({
+        pressed: pressedState 
+      });
     }
   }
 }