Vue.js - push method for object throws Type Error

I am using push() method to add data to an object and receiving an Error:

Uncaught (in promise) TypeError: this.message.push is not a function

Some data is received from an API call, which is to be added to the object.

var price = new Vue({
        delimiters: ["[[","]]"],
        el: '#app',
        data: {
            message: {}
    },
    mounted () {
    {% for i in arr %}
        axios
        .get('https:apicall/symbol={{ x }}')
        .then(response => (this.message.push({name : response.data.price , cost: response.data.price.regularMarketPrice.fmt}))
    {% endfor %}
  }
})

However when I changed:

message: []

and

.then(response => (this.message.push(response.data.price))

it worked fine.

I am using Vue in Django framework and am new to Vue.js

push is an array method not an object method, an array could be initialized as message:[] and an object like message:{}, so you could push a data to an array or assign that data to an object or a property inside that object like :

this.message=response.data.price

or

this.message.price=response.data.price