--- title: class: --- The `class:` directive is a convenient way to conditionally set classes on elements, as an alternative to using conditional expressions inside `class` attributes: ```svelte <!-- These are equivalent --> <div class={isCool ? 'cool' : ''}>...</div> <div class:cool={isCool}>...</div> ``` As with other directives, we can use a shorthand when the name of the class coincides with the value: ```svelte <div class:cool>...</div> ``` Multiple `class:` directives can be added to a single element: ```svelte <div class:cool class:lame={!cool} class:potato>...</div> ```