Say you have a Car component.

You want to add a class to its output based on a prop.

So maybe the prop is called color, and you use it like this in other parts of the app:

<Car color="red">
<Car color="blue">

In your Car component you first need to declare the color prop:

<script>
export default {
  name: 'Car',
  props: {
    color: String
  }
}
</script>

then you can use it in the template part:

<template>
  <div :class="color"></div>
</template>

If you want to add a car class, plus the class determined by the color prop, you can use this syntax:

<template>
  <div :class="['car', color]"></div>
</template>

Happy coding!