Vue: determine observed object type (distinguish between array and object)

Question

I have simple Vue instance:

<html>
  <body>        
    <div id="container">
      <input type="text" id="container" placeholder="enter text" v-model="value">
      <p>{{ value }}</p>
    </div>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/vue/0.11.10/vue.min.js"></script>
    <script>
      new Vue({
        el: '#container',
        data: {
          value: '',
          list: []
        },
        created: function() {
          console.log(typeof this.list); // i would like to determine type of underlaying object
        }
      });
    </script>
  </body>
</html>

https://codepen.io/anon/pen/KxVQEw?editors=1111

How to determine the type of the observed proprety in data lets say .list inside 'created' life cycle hook?

dziraf · Accepted Answer · 2018-08-25 19:59:58Z

11

typeof [] will return "object", same as typeof {}. If you want to know whether it's for example a JSON object or an array you can use varname.constructor.name:

console.log(typeof []) // object
console.log([].constructor.name) // Array

console.log(typeof {}) // object
console.log({}.constructor.name) // Object

In your case:

console.log(this.list.constructor.name) // Array

edited Aug 25, 2018 at 19:59

answered Aug 25, 2018 at 19:48

dziraf

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1 Comment

IT Man Over a year ago

I was surprised but it seems to work as i desire for observers.

gekkedev · Accepted Answer · 2022-03-01 15:54:09Z

1

Although there already is a working answer, I decided to use this alternative as it is less code: Array.isArray

Array.isArray([]) //true
Array.isArray({}) //false

answered Mar 1, 2022 at 15:54

gekkedev

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