How to apply multi classes to an element/ combine conditional static classes

Question

I want to apply multiple css classes to one element. How do I do it? One conditional and one static.

  <p
    class={current === 'overview' ? 'selected' : '' // here I want to add another class named foo}
    on:click={() => (current = 'overview')}
  >

Answer 1

To make life easier you can use the class: directive

<p class="foo" class:selected={current === 'overview'}>

Answer 2

Separate by whitespace according to HTML standard class="{current === 'overview' ? 'selected' : ''} foo"