<div v-for="task in tasks" :key="task.id" v-if="task.completed">
  <ul>
  <li v-text="task.description"></li>
  <input type="checkbox" @change="changeComplete">
  </ul>
</div>




var app = new Vue ({
  el: '#root',
  data:  {
    tasks: [
           {description: 'clean room', completed: true, id: 1},
           {description: 'do homework', completed: true, id: 2},
           {description: 'go to sleep', completed: false, id: 3}
           ]
          },
  methods: {
    changeComplete() {
          this.task.completed = !this.task.completed;
          }
      }
  })