Conditional styling patterns in NextJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is conditional styling in Next.js?

Conditional styling means changing the look of a component based on some condition, like a button changing color when clicked or hovered.

beginner

How can you apply conditional CSS classes in Next.js components?

You can use JavaScript expressions inside the className attribute, for example: className={isActive ? 'active' : 'inactive'}.

intermediate

What is the benefit of using the clsx or classnames library for conditional styling?

These libraries help combine multiple class names easily and cleanly, especially when many conditions affect styles, making code easier to read and maintain.

beginner

How do you conditionally apply inline styles in Next.js?

You can pass a JavaScript object to the style prop with conditional properties, like style={{ color: isError ? 'red' : 'black' }}.

intermediate

Why is it important to keep conditional styling accessible?

Because styling changes can affect readability and usability, ensuring good color contrast and clear focus states helps all users, including those with disabilities.

Which is a correct way to conditionally add a CSS class in Next.js?

A <code>className='active' when isActive</code>

B <code>class='active' if isActive</code>

C <code>className={isActive ? 'active' : ''}</code>

D <code>style={{ active: isActive }}</code>

In JSX, you use JavaScript expressions inside curly braces to conditionally set className.

What does the clsx library help with?

A Combining multiple class names conditionally

B Fetching data from APIs

C Managing component state

D Routing between pages

clsx helps combine class names based on conditions in a clean way.

How can you conditionally change the text color using inline styles?

A <code>color = isError ? 'red' : 'black'</code>

B <code>style={{ color: isError ? 'red' : 'black' }}</code>

C <code>className={isError ? 'red' : 'black'}</code>

D <code>style='color: red' if isError</code>

Inline styles in JSX use a JavaScript object with conditional values.

Why should you consider accessibility in conditional styling?

A To ensure all users can see and interact with content properly

B To make the website load faster

C To reduce the number of CSS files

D To avoid using JavaScript

Good accessibility means styling changes do not harm usability for people with disabilities.

Which React hook is commonly used to toggle a style condition?

A useMemo

B useEffect

C useContext

D useState

useState lets you track and toggle conditions that affect styling.

Explain how you would apply conditional styling to a button in Next.js that changes color when clicked.

Think about toggling a boolean and using it to set className.

Describe why accessibility matters when using conditional styling and give an example.

Consider users with vision impairments or keyboard navigation.