Button styles and variants in Bootsrap - Practice Problems & Coding Challenges

Challenge - 5 Problems

📝 Syntax

intermediate

What is the output of this Bootstrap button code?

Consider the following HTML snippet using Bootstrap classes:

<button class="btn btn-primary">Click Me</button>

What will the button look like when rendered in a browser?

Bootsrap

<button class="btn btn-primary">Click Me</button>

A A green button with black text and shadow

B A red button with white text and sharp corners

C A transparent button with blue text and underline

D A blue button with white text and rounded corners

💡 Hint

Bootstrap's btn-primary class gives a blue background with white text.

The class 'btn-primary' in Bootstrap styles the button with a blue background and white text, along with rounded corners by default.

🧠 Conceptual

intermediate

Which Bootstrap class creates a button with no background and blue text?

You want a button that looks like a link: no background color but blue text. Which Bootstrap class should you use?

A btn-link

B btn-primary

C btn-outline-primary

D btn-secondary

💡 Hint

Think about which class makes buttons look like links.

The 'btn-link' class styles buttons to look like links with no background and blue text by default.

❓ selector

advanced

Which CSS selector targets all Bootstrap buttons with outline style?

Bootstrap uses classes like 'btn-outline-primary' for outline buttons. Which CSS selector matches all buttons with any outline style?

A [class^="btn-outline-"]

B .btn-outline-primary, .btn-outline-secondary, .btn-outline-success

C .btn[class*="outline"]

D .btn-outline

💡 Hint

Look for attribute selectors that match class names starting with a pattern.

The selector [class^="btn-outline-"] matches elements whose class attribute starts with 'btn-outline-', covering all outline button variants.

❓ layout

advanced

How to create a group of buttons that share the same width in Bootstrap?

You want three buttons side by side, each exactly the same width, filling the container evenly. Which Bootstrap approach achieves this?

A Use 'btn-group w-100' and add 'w-100' to each button

B Wrap buttons in 'btn-group' and add 'flex-fill' to each button

C Use 'btn-group' only, no extra classes

D Wrap buttons in 'btn-toolbar' and add 'flex-fill' to each button

💡 Hint

Bootstrap flex utilities help buttons fill space evenly.

Using 'btn-group' with 'flex-fill' on each button makes them share equal width inside the group.

❓ accessibility

expert

Which attribute improves accessibility for icon-only Bootstrap buttons?

You have a Bootstrap button that only shows an icon (no text). Which attribute should you add to make it accessible for screen readers?

Bootsrap

<button class="btn btn-primary"><i class="bi bi-star"></i></button>

A title="Star button"

B role="button"

C aria-label="Star button"

D alt="Star icon"

💡 Hint

Screen readers need descriptive text for buttons without visible text.

The 'aria-label' attribute provides an accessible name for screen readers when the button has no visible text.

Practice

1. Which Bootstrap class combination correctly creates a blue primary button?

easy

A. btn btn-secondary

B. btn btn-danger

C. btn btn-warning

D. btn btn-primary

Solution

1. Step 1: Understand Bootstrap button base class

   All Bootstrap buttons require the base class btn to apply button styles.

2. Step 2: Identify the variant for blue color

   The btn-primary class applies the blue color variant to the button.

3. Final Answer:

   <button class='btn btn-primary'> -> Option D

4. Quick Check:

   Blue primary button = btn btn-primary [OK]

Hint: Primary buttons always use btn-primary class [OK]

Common Mistakes:

• Using btn-danger for blue instead of red
• Omitting the base btn class
• Confusing btn-secondary with btn-primary

2. Which of the following is the correct syntax to create a small green success button in Bootstrap?

easy

A. <button class='btn btn-primary btn-sm'>Success</button>

B. <button class='btn btn-success btn-sm'>Success</button>

C. <button class='btn btn-success btn-lg'>Success</button>

D. <button class='btn btn-danger btn-sm'>Success</button>

Solution

1. Step 1: Identify the success variant class

   The green color for success buttons is applied with btn-success.

2. Step 2: Choose the small size modifier

   The class btn-sm makes the button smaller in size.

3. Final Answer:

   <button class='btn btn-success btn-sm'>Success</button> -> Option B

4. Quick Check:

   Small green button = btn-success btn-sm [OK]

Hint: Use btn-sm for small size and btn-success for green [OK]

Common Mistakes:

• Using btn-lg instead of btn-sm for small size
• Mixing btn-primary with success text
• Forgetting the btn base class

3. What color will the button have when using this code?

<button class='btn btn-warning btn-lg'>Warning</button>

medium

A. Yellow

B. Red

C. Blue

D. Green

Solution

1. Step 1: Identify the variant class

   The class btn-warning applies a yellow/orange color to the button.

2. Step 2: Understand the size modifier

   The btn-lg class makes the button larger but does not affect color.

3. Final Answer:

   Yellow -> Option A

4. Quick Check:

   btn-warning = Yellow color [OK]

Hint: Warning buttons use btn-warning for yellow color [OK]

Common Mistakes:

• Confusing btn-warning with btn-danger (red)
• Thinking btn-lg changes color
• Mixing btn-primary with warning text

4. Identify the error in this Bootstrap button code:

<button class='btn btn-info btn-small'>Info</button>

medium

A. btn-info is not a valid variant

B. Button text should be uppercase

C. btn-small is not a valid size class

D. Missing btn base class

Solution

1. Step 1: Check variant class validity

   btn-info is a valid Bootstrap variant for a light blue button.

2. Step 2: Verify size class correctness

   Bootstrap uses btn-sm and btn-lg for sizes, not btn-small.

3. Final Answer:

   btn-small is not a valid size class -> Option C

4. Quick Check:

   Size classes are btn-sm or btn-lg only [OK]

Hint: Use btn-sm or btn-lg for sizes, not btn-small [OK]

Common Mistakes:

• Using btn-small instead of btn-sm
• Assuming btn-info is invalid
• Forgetting btn base class (not the case here)

5. You want a dark-themed button that is large and has a warning color. Which class combination achieves this correctly?

hard

A. btn btn-dark btn-lg

B. btn btn-warning btn-lg

C. btn btn-warning btn-dark btn-lg

D. btn btn-dark-warning btn-lg

Solution

1. Step 1: Understand Bootstrap button variants

   Bootstrap does not have a combined variant like btn-dark-warning. Variants are separate classes like btn-warning (yellow) or btn-dark (dark gray).

2. Step 2: Choose the correct variant for dark theme

   The dark theme is applied by btn-dark. Adding btn-warning alongside it causes conflicting colors.

3. Step 3: Apply large size modifier

   The btn-lg class correctly makes the button large.

4. Final Answer:

   btn btn-dark btn-lg -> Option A

5. Quick Check:

   Use one variant class plus size class [OK]

Hint: Use only one variant class with size class for correct style [OK]

Common Mistakes:

• Combining multiple variant classes causing style conflicts
• Using non-existent combined variant classes
• Forgetting the btn base class