[Vuejs]-Is it possible to use an iterated element in a "v-for" as a object key in data property?

It’s not working because of the reactivity issue. Just replace the updateDate method with following function and it works.

    updateDate: function (data) {
    //this.date[data.dateIndex] = data.date;
    this.$set(this.date,data.dateIndex,data.date)
  },

jsFiddle – http://jsfiddle.net/ynug7kLx/