Card images and overlays in Bootsrap - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a card image in Bootstrap?

A card image is an image placed inside a Bootstrap card component, usually at the top or bottom, to visually represent the card content.

beginner

How do you add an overlay on a card image in Bootstrap?

You add an overlay by placing a card-img-overlay div inside the card with the image. This overlay can contain text or other content displayed over the image.

beginner

Which Bootstrap class makes the card image fill the card width automatically?

The class card-img-top or card-img-bottom makes the image fill the card's width at the top or bottom respectively.

intermediate

What is the purpose of card-img-overlay in Bootstrap cards?

It allows you to place text or other content on top of the card image, creating a layered effect with the image as background.

intermediate

Can you use multiple elements inside a card-img-overlay? If yes, give an example.

Yes, you can add headings, paragraphs, buttons, or any HTML inside card-img-overlay. For example, a heading and a button can appear over the image.

Which class is used to place an image at the top of a Bootstrap card?

A card-img-bottom

B card-img-overlay

C card-img-top

D card-image

The card-img-top class places the image at the top of the card.

What does the card-img-overlay class do?

A Places content over the card image as an overlay

B Adds a border around the card image

C Resizes the card image

D Removes the card image

The card-img-overlay class places content like text or buttons over the card image.

Where should the card-img-overlay div be placed in the card structure?

A Outside the card

B Inside the card but outside the image

C Before the card element

D Inside the card and inside the image container

The card-img-overlay should be inside the card but outside the image.

Which of these is NOT a valid Bootstrap card image class?

A card-img-center

B card-img-bottom

C card-img-top

D card-img-overlay

card-img-center is not a valid Bootstrap class.

What kind of content can you put inside a card-img-overlay?

A Only links

B Only text

C Only images

D Any HTML content like text, buttons, or headings

You can put any HTML content inside card-img-overlay, such as text, buttons, or headings.

Explain how to create a Bootstrap card with an image and text overlay on top of the image.

Think about layering content on top of an image inside a card.

Describe the difference between card-img-top and card-img-overlay in Bootstrap cards.

One is for image placement, the other is for layering content.

Practice

1. What is the purpose of the card-img-overlay class in Bootstrap cards?

easy

A. To add a border around the card image

B. To place text or content on top of the card image

C. To resize the card image automatically

D. To add a shadow effect to the card image

Solution

1. Step 1: Understand the role of card-img-overlay

   This class is used to add content that appears over the card image, such as text or buttons.

2. Step 2: Compare with other options

   Other options describe effects or styles not related to overlays, so they are incorrect.

3. Final Answer:

   To place text or content on top of the card image -> Option B

4. Quick Check:

   Overlay content = card-img-overlay = B [OK]

Hint: Overlay means content on top of image [OK]

Common Mistakes:

• Confusing overlay with image resizing
• Thinking overlay adds borders or shadows
• Ignoring that overlay is for layering content

2. Which of the following is the correct way to add an image inside a Bootstrap card with an overlay?

easy

A. Text

B. Text

C. Text

D. Text

Solution

1. Step 1: Check correct structure for image and overlay

   The image uses card-img class and the overlay content uses card-img-overlay inside the card container.

2. Step 2: Validate

   Text

   structure

   Text
   correctly places the image first with card-img and overlay div after with card-img-overlay.

3. Final Answer:

   <div class='card'><img src='img.jpg' class='card-img'><div class='card-img-overlay'>Text</div></div> -> Option D

4. Quick Check:

   Image class = card-img, Overlay class = card-img-overlay [OK]

Hint: Image gets card-img, overlay gets card-img-overlay [OK]

Common Mistakes:

• Putting overlay class on the image tag
• Placing overlay outside the card container
• Mixing up class names between image and overlay

3. What will be the visual result of this code?

<div class='card' style='width: 18rem;'>
  <img src='photo.jpg' class='card-img' alt='Sample Image'>
  <div class='card-img-overlay'>
    <h5 class='card-title'>Hello</h5>
    <p class='card-text'>Overlay text</p>
  </div>
</div>

medium

A. A card with the image and text displayed on top of the image

B. A card with the image below and text below the image

C. Only the text is visible, image is hidden

D. The image is stretched and text is outside the card

Solution

1. Step 1: Understand card-img and card-img-overlay behavior

   The image fills the card area and the overlay places text on top of the image.

2. Step 2: Visualize the overlay content

   The card-img-overlay content appears layered on the image, so text is visible over the picture.

3. Final Answer:

   A card with the image and text displayed on top of the image -> Option A

4. Quick Check:

   Overlay text on image = card-img-overlay = C [OK]

Hint: Overlay means text appears on top of image [OK]

Common Mistakes:

• Thinking overlay text appears below image
• Assuming image is hidden by overlay
• Confusing overlay with separate card sections

4. Identify the error in this Bootstrap card code:

<div class='card'>
  <div class='card-img-overlay'>Overlay Text</div>
  <img src='pic.jpg' class='card-img' alt='Pic'>
</div>

medium

A. The card-img-overlay class should be on the image tag

B. The image tag should not have the class 'card-img'

C. The overlay div should come after the image tag inside the card

D. The card div is missing a width style

Solution

1. Step 1: Check the order of image and overlay

   The overlay content must come after the image tag to appear on top visually.

2. Step 2: Verify class usage

   The image should have card-img and overlay a separate div with card-img-overlay. The order matters for layering.

3. Final Answer:

   The overlay div should come after the image tag inside the card -> Option C

4. Quick Check:

   Overlay after image = layering correct = A [OK]

Hint: Overlay must be after image tag for layering [OK]

Common Mistakes:

• Placing overlay before image causing hidden text
• Misusing classes on wrong elements
• Ignoring layering order in HTML structure

5. You want to create a Bootstrap card with a dark semi-transparent overlay on the image and white text on top. Which approach is best?

hard

A. Use card-img for the image, card-img-overlay with a custom CSS class adding a dark background with opacity, and white text classes

B. Add a dark filter directly on the image tag and place text below the image

C. Use only card-img-overlay with a dark background but no image tag

D. Place the image inside card-img-overlay and add white text inside the image tag

Solution

1. Step 1: Understand layering with card-img and card-img-overlay

   The image uses card-img and overlay content uses card-img-overlay for layering text on image.

2. Step 2: Add dark semi-transparent background and white text

   Custom CSS on card-img-overlay can add a dark background with opacity. White text classes ensure readability.

3. Final Answer:

   Use card-img for image, card-img-overlay with custom dark background and white text -> Option A

4. Quick Check:

   Overlay + custom dark bg + white text = D [OK]

Hint: Overlay div with semi-transparent bg and white text works best [OK]

Common Mistakes:

• Trying to filter image without overlay div
• Placing image inside overlay div incorrectly
• Not adding text color for contrast