Validating select elements

The next element is a single <select> element with multiple <option> elements as follows:

// src/components/basic.vue
<select v-model="form.favourite">
  <option disabled value="">Please select one</option>
  <option value="On the Origin of Species">On the Origin of 
   Species</option>
  <option value="A Brief History of Time">A Brief History of Time</option>
  <option value="The Selfish Gene">The Selfish Gene</option>
</select>

export default {
  data () {
    return {
      form: { favourite: null }
    }
  },
  methods:{
    checkForm (e) {
      this.errors = []
      if (!this.form.favourite) {
        this.errors.push('Favourite required')
      }
    }
  }
}

And the last one is multiple <select> elements with multiple <option> elements that are bound to the same Array, that is, favourites: []:

// src/components...