Border utilities in Bootsrap - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of Bootstrap's border utilities?

Bootstrap's border utilities let you quickly add or remove borders on elements without writing custom CSS. They help style borders easily using predefined classes.

beginner

How do you add a border to all sides of an element using Bootstrap?

Use the class .border. This adds a 1px solid border on all four sides of the element.

beginner

Which class removes the border from an element in Bootstrap?

The class .border-0 removes all borders from the element.

beginner

How can you add a border only to the top side of an element?

Use the class .border-top to add a border only on the top side.

beginner

How do you change the border color using Bootstrap border utilities?

Add a color class like <code>.border-primary</code>, <code>.border-success</code>, or <code>.border-danger</code> to change the border color to Bootstrap's theme colors.

Which class adds a border to all sides of an element?

A .border-0

B .border-top

C .border-none

D .border

The class .border adds a border on all sides of the element.

How do you remove all borders from an element?

A .border-remove

B .border-0

C .no-border

D .border-none

The class .border-0 removes all borders from the element.

Which class adds a border only on the bottom side?

A .border-bottom

B .border-left

C .border-right

D .border-top

The class .border-bottom adds a border only on the bottom side.

To change the border color to Bootstrap's primary color, which class should you use?

A .border-theme-primary

B .border-color-primary

C .border-primary

D .border-blue

The class .border-primary changes the border color to Bootstrap's primary theme color.

Which class adds a border only on the left side?

A .border-left

B .border-right

C .border-top

D .border-bottom

The class .border-left adds a border only on the left side.

Explain how to add and remove borders on specific sides of an element using Bootstrap border utilities.

Think about the classes that target all sides vs. individual sides.

Describe how to change the color of borders using Bootstrap border utilities.

Bootstrap uses color utility classes for borders similar to text and background colors.

Practice

1. Which Bootstrap class adds a border to all sides of an element?

easy

A. border

B. border-top

C. border-none

D. border-left

Solution

1. Step 1: Understand the border utility classes

   Bootstrap's border class adds a border on all four sides of an element.

2. Step 2: Compare with side-specific classes

   Classes like border-top or border-left add borders only on one side, not all sides.

3. Final Answer:

   border -> Option A

4. Quick Check:

   All sides border = border [OK]

Hint: Use border for all sides border fast [OK]

Common Mistakes:

• Confusing border-top as all sides border
• Using border-none to add border
• Thinking border-left adds all borders

2. Which class correctly removes the border from an element in Bootstrap?

easy

A. border-remove

B. no-border

C. border-0

D. border-none

Solution

1. Step 1: Identify the Bootstrap class for removing borders

   Bootstrap uses border-0 to remove all borders from an element.

2. Step 2: Check other options for validity

   Classes like border-remove, no-border, and border-none are not valid Bootstrap classes.

3. Final Answer:

   border-0 -> Option C

4. Quick Check:

   Remove border = border-0 [OK]

Hint: Use border-0 to remove borders quickly [OK]

Common Mistakes:

• Using non-existent classes like border-none
• Assuming border-remove works
• Confusing border-0 with adding borders

3. What will be the visible border effect of this HTML snippet?

<div class="border-top border-danger p-3">Hello</div>

medium

A. A red border on the bottom side only

B. A red border on all sides

C. No border visible

D. A red border on the top side only

Solution

1. Step 1: Analyze the classes used

   The class border-top adds a border only on the top side. The class border-danger colors the border red.

2. Step 2: Understand the combined effect

   Only the top border will be visible and it will be red. Other sides have no border.

3. Final Answer:

   A red border on the top side only -> Option D

4. Quick Check:

   border-top + border-danger = red top border [OK]

Hint: Combine side + color classes for specific colored borders [OK]

Common Mistakes:

• Thinking border-danger adds border on all sides
• Assuming border-top adds border on all sides
• Ignoring the color class effect

4. You want to add a border only on the left side of a button, but your code uses border-left-3. Why does the border not appear?

medium

A. Because border-left-3 is not a valid Bootstrap class

B. Because the button has no padding

C. Because border-left needs a color class to show

D. Because borders only work on divs, not buttons

Solution

1. Step 1: Check Bootstrap border width classes

   Bootstrap uses border for border presence and border-1, border-2, etc. for width, but not combined with side like border-left-3.

2. Step 2: Understand correct usage

   To add a left border with width, use border-start plus border-3 or just border-start with color. border-left-3 is invalid.

3. Final Answer:

   border-left-3 is not a valid Bootstrap class -> Option A

4. Quick Check:

   Invalid class name = no border shown [OK]

Hint: Use valid Bootstrap classes; no combined side-width classes [OK]

Common Mistakes:

• Using invalid combined classes like border-left-3
• Assuming buttons can't have borders
• Forgetting to add color class for visibility

5. You want to create a card with a thick blue border only on the bottom side using Bootstrap. Which combination of classes achieves this?

hard

A. border border-4 border-primary

B. border-bottom border-4 border-primary

C. border-bottom-4 border-primary

D. border-bottom border-primary border-4

Solution

1. Step 1: Identify classes for border side and width

   border-bottom adds border only on the bottom side. border-4 sets border thickness to 4 (thick).

2. Step 2: Add color class

   border-primary colors the border blue (Bootstrap primary color).

3. Step 3: Check class order and validity

   Order does not affect Bootstrap border utilities, so border-bottom border-4 border-primary is correct. border-bottom-4 is invalid.

4. Final Answer:

   border-bottom border-4 border-primary -> Option B

5. Quick Check:

   Bottom thick blue border = border-bottom border-4 border-primary [OK]

Hint: Combine side + width + color classes for custom borders [OK]

Common Mistakes:

• Using invalid class border-bottom-4
• Adding border on all sides instead of bottom only
• Forgetting to add border width class