TouchableOpacity and TouchableHighlight in React Native - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ ui_behavior

intermediate

Difference in Visual Feedback Between TouchableOpacity and TouchableHighlight

When you press a button wrapped in TouchableOpacity versus one wrapped in TouchableHighlight, what visual effect do you see?

A TouchableOpacity shows a colored overlay, while TouchableHighlight dims the button's opacity.

B Both TouchableOpacity and TouchableHighlight show a ripple effect on press.

C TouchableOpacity dims the button's opacity, while TouchableHighlight shows a colored overlay.

D Neither TouchableOpacity nor TouchableHighlight provide any visual feedback on press.

💡 Hint

Think about how the button looks when you tap it in each case.

TouchableOpacity reduces the opacity of its child component to show feedback, making it look faded. TouchableHighlight adds a colored overlay (highlight) on top of the child component.

❓ lifecycle

intermediate

TouchableHighlight Underlay Color Behavior

What happens if you do not set the underlayColor prop on a TouchableHighlight component?

A TouchableHighlight will use a default gray color as the underlay when pressed.

B TouchableHighlight will throw a runtime error because underlayColor is required.

C TouchableHighlight will not show any visual feedback when pressed.

D TouchableHighlight will crash the app on press.

💡 Hint

Try pressing a TouchableHighlight without underlayColor set.

If underlayColor is not specified, TouchableHighlight uses a default gray color for the underlay to show feedback.

📝 Syntax

advanced

Correct Usage of TouchableOpacity with onPress

Which code snippet correctly implements a TouchableOpacity button that logs 'Pressed!' when tapped?

React Native

import React from 'react';
import { TouchableOpacity, Text } from 'react-native';

export default function MyButton() {
  return (
    <TouchableOpacity onPress={() => console.log('Pressed!')}>
      <Text>Press Me</Text>
    </TouchableOpacity>
  );
}

A TouchableOpacity onPress={() => console.log('Pressed!')}><Text>Press Me</Text></TouchableOpacity>

B TouchableOpacity(onPress={() => console.log('Pressed!')}) {<Text>Press Me</Text>}

C >yticapOelbahcuoT/<>txeT/<eM sserP>txeT<>})'!desserP'(gol.elosnoc >= )({=sserPno yticapOelbahcuoT<

D <TouchableOpacity onPress={() => console.log('Pressed!')}><Text>Press Me</Text></TouchableOpacity>

💡 Hint

Remember JSX syntax requires tags to be enclosed in angle brackets.

Option D correctly uses JSX syntax with angle brackets and proper nesting. Options A and B are missing angle brackets or use invalid syntax. Option D is identical to C.

🔧 Debug

advanced

Why Does TouchableHighlight Not Show Feedback?

You wrapped a button in TouchableHighlight but pressing it does not show any visual feedback. What is the most likely cause?

A TouchableHighlight must be wrapped inside a ScrollView to show feedback.

B The child component has a transparent background, so the underlay color is not visible.

C TouchableHighlight only works on Android, not iOS.

D TouchableHighlight requires an onPress prop to show feedback, and it is missing.

💡 Hint

Check the background color of the child inside TouchableHighlight.

If the child component has a transparent background, the underlay color will not be visible, so no feedback appears. Adding a background color to the child fixes this.

🧠 Conceptual

expert

Choosing Between TouchableOpacity and TouchableHighlight

You want a button that shows a subtle fade effect on press and works well with images and text. Which component is best to use and why?

A TouchableOpacity, because it reduces opacity smoothly and works well with any child content.

B TouchableHighlight, because it adds a colored overlay that works better with images only.

C TouchableHighlight, because it disables opacity changes and only works with text children.

D TouchableOpacity, because it requires setting underlayColor for visual feedback.

💡 Hint

Think about the visual effect and compatibility with different child elements.

TouchableOpacity reduces the opacity of its children, creating a subtle fade effect that works well with images and text. TouchableHighlight adds a colored overlay which may not always look good with images.

Practice

1. What is the main visual difference between TouchableOpacity and TouchableHighlight in React Native?

easy

A. Both components fade the button but with different speeds.

B. TouchableOpacity shows a colored highlight, TouchableHighlight fades the button.

C. TouchableOpacity fades the button, TouchableHighlight shows a colored highlight.

D. Both components show a colored highlight but with different colors.

Solution

1. Step 1: Understand TouchableOpacity behavior

   TouchableOpacity reduces the opacity of the button to create a fading effect on tap.

2. Step 2: Understand TouchableHighlight behavior

   TouchableHighlight adds a colored overlay highlight on tap instead of fading.

3. Final Answer:

   TouchableOpacity fades the button, TouchableHighlight shows a colored highlight. -> Option C

4. Quick Check:

   Opacity fade = TouchableOpacity, Highlight color = TouchableHighlight [OK]

Hint: Opacity fade means TouchableOpacity, colored highlight means TouchableHighlight [OK]

Common Mistakes:

• Confusing which component fades vs highlights
• Thinking both behave the same visually
• Assuming TouchableHighlight fades opacity

2. Which of the following is the correct way to import TouchableOpacity in a React Native component?

easy

A. import { TouchableOpacity } from 'react-native';

B. import TouchableOpacity from 'react-native';

C. import TouchableOpacity from 'react-native-touchable';

D. import { TouchableOpacity } from 'react-native-touchable';

Solution

1. Step 1: Check React Native import syntax

   React Native exports TouchableOpacity as a named export, so it must be imported with curly braces.

2. Step 2: Verify package source

   TouchableOpacity is part of the core react-native package, not a separate package.

3. Final Answer:

   import { TouchableOpacity } from 'react-native'; -> Option A

4. Quick Check:

   Named import from 'react-native' = import { TouchableOpacity } from 'react-native'; [OK]

Hint: Use curly braces for named imports from 'react-native' [OK]

Common Mistakes:

• Using default import without braces
• Importing from wrong package name
• Missing curly braces around TouchableOpacity

3. What will happen when the user taps the button in this code snippet?

import React from 'react';
import { TouchableHighlight, Text } from 'react-native';

export default function App() {
  return (
     alert('Pressed!')}>
      Tap me
    
  );
}

medium

A. The button fades out on tap and shows an alert.

B. The button shows a red highlight on tap and shows an alert.

C. Nothing happens on tap because underlayColor is invalid.

D. The button shows a yellow highlight on tap and shows an alert.

Solution

1. Step 1: Identify component behavior

   TouchableHighlight uses the underlayColor prop to show a colored highlight when pressed.

2. Step 2: Check the underlayColor value and onPress

   The underlayColor is set to 'yellow', so the highlight will be yellow. The onPress triggers an alert with 'Pressed!'.

3. Final Answer:

   The button shows a yellow highlight on tap and shows an alert. -> Option D

4. Quick Check:

   TouchableHighlight + underlayColor yellow + alert onPress = The button shows a yellow highlight on tap and shows an alert. [OK]

Hint: TouchableHighlight uses underlayColor for highlight color [OK]

Common Mistakes:

• Confusing fade effect with TouchableOpacity
• Assuming underlayColor changes text color
• Ignoring the alert onPress effect

4. Identify the error in this React Native code using TouchableOpacity:

import React from 'react';
import { TouchableOpacity, Text } from 'react-native';

export default function App() {
  return (
     console.log('Pressed')}
      Click me
    
  );
}

medium

A. Missing closing bracket ">" on TouchableOpacity opening tag.

B. Incorrect import statement for TouchableOpacity.

C. The onPress function should return a value.

D. Text component cannot be a child of TouchableOpacity.

Solution

1. Step 1: Check JSX syntax for TouchableOpacity

   The opening tag for TouchableOpacity is missing the closing ">" before the child Text component.

2. Step 2: Verify other parts

   Imports are correct, onPress does not need to return a value, and Text can be a child of TouchableOpacity.

3. Final Answer:

   Missing closing bracket ">" on TouchableOpacity opening tag. -> Option A

4. Quick Check:

   JSX tags must close properly = Missing closing bracket ">" on TouchableOpacity opening tag. [OK]

Hint: Check JSX tags for missing > or /> [OK]

Common Mistakes:

• Ignoring missing closing bracket errors
• Thinking onPress must return a value
• Believing Text cannot be child of TouchableOpacity

5. You want a button that shows a blue highlight when pressed and also reduces opacity slightly. Which approach correctly combines TouchableHighlight and TouchableOpacity to achieve this effect?

hard

A. Wrap TouchableHighlight inside TouchableOpacity with underlayColor='blue'.

B. Wrap TouchableOpacity inside TouchableHighlight with underlayColor='blue'.

C. Use only TouchableOpacity with underlayColor='blue' prop.

D. Use only TouchableHighlight with activeOpacity={0.5} prop.

Solution

1. Step 1: Understand each component's effect

   TouchableHighlight provides the colored highlight via underlayColor. TouchableOpacity controls opacity fade via activeOpacity.

2. Step 2: Combine effects by nesting

   Wrapping TouchableOpacity inside TouchableHighlight applies the highlight outside and opacity fade inside, combining both effects.

3. Step 3: Check other options

   Wrap TouchableHighlight inside TouchableOpacity with underlayColor='blue'. reverses nesting, which breaks highlight effect. Options C and D misuse props not supported by those components.

4. Final Answer:

   Wrap TouchableOpacity inside TouchableHighlight with underlayColor='blue'. -> Option B

5. Quick Check:

   Nesting TouchableOpacity inside TouchableHighlight = Wrap TouchableOpacity inside TouchableHighlight with underlayColor='blue'. [OK]

Hint: Wrap opacity inside highlight to combine effects [OK]

Common Mistakes:

• Reversing component nesting order
• Using unsupported props on components
• Expecting one component to do both effects alone