Carousel programmatic control in Bootsrap - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to select the carousel element by its ID.

Bootsrap

const carouselElement = document.querySelector('[1]');

Drag options to blanks, or click blank then click option'

A#myCarousel

B.carousel

CmyCarousel

Dcarousel

Attempts:

3 left

💡 Hint

Common Mistakes

Using class selector '.' instead of ID selector '#'.

Using the ID name without '#' prefix.

Use #myCarousel to select the element with ID myCarousel.

2fill in blank

medium

Complete the code to create a Bootstrap Carousel instance from the element.

Bootsrap

const carousel = new bootstrap.Carousel([1]);

Drag options to blanks, or click blank then click option'

AmyCarousel

Bdocument.querySelector('#myCarousel')

CcarouselElement

D'#myCarousel'

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a selector string instead of the element.

Passing an undefined variable.

Pass the selected DOM element carouselElement to the Carousel constructor.

3fill in blank

hard

Fix the error in the code to move the carousel to the next slide programmatically.

Bootsrap

carousel.[1]();

Drag options to blanks, or click blank then click option'

AgoNext

Bnext

CslideNext

DnextSlide

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect method names like 'nextSlide' or 'slideNext'.

Trying to call a non-existent method.

The correct method to move to the next slide is next().

4fill in blank

hard

Fill both blanks to pause and then cycle the carousel programmatically.

Bootsrap

carousel.[1]();
carousel.[2]();

Drag options to blanks, or click blank then click option'

Apause

Bcycle

Cstop

Dstart

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'stop' or 'start' which are not Bootstrap Carousel methods.

Mixing the order of pause and cycle.

Use pause() to stop the carousel and cycle() to start it again.

5fill in blank

hard

Fill all three blanks to move the carousel to a specific slide index programmatically.

Bootsrap

carousel.[1]([2]);

// Example: move to slide number [3]

Drag options to blanks, or click blank then click option'

Ato

B3

C2

Dslide

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method names like 'slide'.

Confusing slide number with zero-based index.

The method to(index) moves the carousel to the slide at the given zero-based index. Here, index 2 means the third slide.

Practice

1. What does programmatic control of a Bootstrap carousel allow you to do?

easy

A. Move slides using JavaScript commands

B. Change the carousel's color scheme

C. Add new images to the carousel dynamically

D. Automatically resize the carousel on window resize

Solution

1. Step 1: Understand programmatic control meaning

   Programmatic control means controlling the carousel with code, not just user clicks.

2. Step 2: Identify what JavaScript commands do

   JavaScript commands let you move slides forward, backward, or jump to a specific slide.

3. Final Answer:

   Move slides using JavaScript commands -> Option A

4. Quick Check:

   Programmatic control = move slides with code [OK]

Hint: Programmatic means controlling with code, not style [OK]

Common Mistakes:

• Confusing programmatic control with styling changes
• Thinking it adds images automatically
• Assuming it resizes carousel automatically

2. Which JavaScript method correctly moves a Bootstrap carousel to the next slide?

easy

A. carousel.next()

B. document.carousel.nextSlide()

C. carousel.slideNext()

D. $('#carouselExample').carousel('next')

Solution

1. Step 1: Recall Bootstrap carousel JavaScript syntax

   Bootstrap uses jQuery style calls like $('#id').carousel('method').

2. Step 2: Identify correct method for next slide

   The method to go to next slide is 'next', so $('#carouselExample').carousel('next') is correct.

3. Final Answer:

   $('#carouselExample').carousel('next') -> Option D

4. Quick Check:

   Use $('#id').carousel('next') to move next [OK]

Hint: Bootstrap carousel uses $('#id').carousel('method') syntax [OK]

Common Mistakes:

• Using non-existent methods like carousel.next()
• Trying to call methods on document.carousel
• Using camelCase method names not in Bootstrap API

3. Given this code snippet, what slide will be shown after execution?

$('#myCarousel').carousel(2);

Assuming the carousel has 4 slides indexed 0 to 3.

medium

A. Slide 0

B. Slide 1

C. Slide 2

D. Slide 3

Solution

1. Step 1: Understand carousel method with number argument

   Calling carousel(n) moves the carousel to slide number n (zero-based index).

2. Step 2: Identify which slide index 2 refers to

   Index 2 means the third slide (0,1,2), so slide 2 will be shown.

3. Final Answer:

   Slide 2 -> Option C

4. Quick Check:

   carousel(2) shows slide index 2 [OK]

Hint: carousel(n) jumps to slide n (zero-based) [OK]

Common Mistakes:

• Thinking carousel(2) moves 2 slides forward
• Confusing slide numbers starting at 1
• Assuming carousel(2) triggers next slide

4. What is wrong with this code to pause a Bootstrap carousel?

document.getElementById('carouselExample').carousel('pause');

medium

A. The method name should be 'stop' instead of 'pause'

B. carousel method is not available on DOM element directly

C. Missing parentheses after 'carousel'

D. The ID selector should use '#' in getElementById

Solution

1. Step 1: Understand how Bootstrap carousel methods are called

   Bootstrap carousel methods are called on jQuery objects, not plain DOM elements.

2. Step 2: Identify why getElementById fails

   getElementById returns a DOM element without jQuery methods, so .carousel('pause') is undefined.

3. Final Answer:

   carousel method is not available on DOM element directly -> Option B

4. Quick Check:

   Use jQuery selector, not getElementById, for carousel methods [OK]

Hint: Use jQuery selector $('#id'), not getElementById, for carousel [OK]

Common Mistakes:

• Trying to call carousel on plain DOM element
• Using wrong method name 'stop' instead of 'pause'
• Adding '#' inside getElementById argument

5. You want to programmatically jump to the last slide of a Bootstrap carousel with 5 slides. Which code snippet correctly does this?

hard

A. $('#carouselExample').carousel(4);

B. $('#carouselExample').carousel('last');

C. $('#carouselExample').carousel('to', 5);

D. $('#carouselExample').carousel.slide(5);

Solution

1. Step 1: Determine last slide index for 5 slides

   Slides are zero-indexed, so last slide index is 4 (0 to 4).

2. Step 2: Use correct method to jump to slide by index

   Calling carousel(4) jumps to slide index 4. Other options use invalid methods or indexes.

3. Final Answer:

   $('#carouselExample').carousel(4); -> Option A

4. Quick Check:

   Use carousel(lastIndex) to jump to last slide [OK]

Hint: Last slide index = total slides - 1; use carousel(index) [OK]

Common Mistakes:

• Using 'last' as method which doesn't exist
• Passing slide number out of range (5 instead of 4)
• Using non-existent carousel.slide() method