Svelte lets you bind JavaScript values to element dimensions as well as the elements themselves. If, for example, we wanted to use the height of an element in JavaScript, we can use Svelte’s in-built syntactic sugar. First, we add `bind:clientHeight={headerHeight}` amid the elements attributes in its markup. This sets the JavaScript variable `headerHeight` to the element height. To finish off, we just need to declare the variable in our script tag: `let headerHeight;`. That’s all there is to it. You can set width too. There is a further shortcut. For that to work, though, the JavaScript variable needs to be named `clientHeight`. In this case, we just add `bind:clientHeight` on the element.