Dropdown button basics in Bootsrap - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ rendering

intermediate

What is the visual output of this Bootstrap dropdown button code?

Given the following HTML code using Bootstrap 5, what will the user see when the page loads?

Bootsrap

<div class="dropdown">
  <button class="btn btn-primary dropdown-toggle" type="button" data-bs-toggle="dropdown" aria-expanded="false">
    Choose an option
  </button>
  <ul class="dropdown-menu">
    <li><a class="dropdown-item" href="#">Option 1</a></li>
    <li><a class="dropdown-item" href="#">Option 2</a></li>
    <li><a class="dropdown-item" href="#">Option 3</a></li>
  </ul>
</div>

A A blue button labeled 'Choose an option' with a downward arrow. The dropdown menu is hidden until clicked.

B A list of three options visible on the page with no button.

C A red button labeled 'Choose an option' with no dropdown functionality.

D A blue button labeled 'Choose an option' with the dropdown menu always visible below it.

💡 Hint

Think about how Bootstrap dropdown buttons behave by default before interaction.

Bootstrap dropdown buttons show a button with a label and a downward arrow. The menu is hidden initially and appears only when the button is clicked.

❓ accessibility

intermediate

Which attribute improves accessibility for this Bootstrap dropdown button?

Consider this button element in a Bootstrap dropdown: Which attribute should be added to improve screen reader accessibility?

A data-toggle="dropdown"

B aria-expanded="false"

C role="button"

D tabindex="-1"

💡 Hint

Screen readers need to know if the dropdown is open or closed.

The aria-expanded attribute tells assistive technologies whether the dropdown is currently expanded or collapsed, improving accessibility.

📝 Syntax

advanced

What error occurs with this dropdown button code?

Examine this snippet:

• Save
• Delete

But the dropdown does not open when clicked. What is the most likely cause?

A The dropdown-menu must be a <div> instead of <ul>

B Incorrect class name on button (should be btn-primary)

C The aria-expanded attribute must be true initially

D Missing Bootstrap JavaScript bundle inclusion

💡 Hint

Bootstrap dropdowns need JavaScript to toggle visibility.

Without including Bootstrap's JavaScript bundle, the dropdown toggle won't work because the click event is not handled.

❓ selector

advanced

Which CSS selector targets only the dropdown toggle button inside a dropdown?

You want to style only the button that toggles the dropdown inside this structure:

...

Which CSS selector correctly targets only the toggle button?

A .dropdown > button.dropdown-toggle

B .dropdown .dropdown-menu button

C .dropdown-menu + button

D button.btn-info

💡 Hint

Look for a selector that targets a button with class dropdown-toggle directly inside .dropdown.

The selector '.dropdown > button.dropdown-toggle' selects any button with class dropdown-toggle that is a direct child of an element with class dropdown.

❓ layout

expert

How to make a Bootstrap dropdown button full width inside a container?

You have this dropdown button inside a container:

...

You want the button to stretch to fill the container's width responsively. Which is the best way?

A Wrap the button in a flex container with justify-content-center

B Add style="width: 100px" to the button element

C Add class w-100 to the button element

D Add class dropdown-menu-end to the dropdown-menu

💡 Hint

Bootstrap has utility classes for width control.

The w-100 class sets width to 100% making the button fill the container's width responsively.