title: Vue warn - Cannot use 'in' operator to search for '[object Array]'
body: <p>Well,</p>
  
  <p>I'm trying to do a project of an a Shopping cart with vue.js, and the browser Console is showing this error:</p>
  
  <blockquote>
    <p>vue.common.js:576 [Vue warn]: Error in created hook: "TypeError: Cannot use 'in' operator to search for '[object Array]' in products"</p>
  </blockquote>
  
  <pre><code>// App.vue
  
  &lt;template&gt;
    &lt;div class="container"&gt;
        &lt;div class="products"&gt;
          &lt;div class="clearfix"&gt;
            &lt;product v-for="product in products" :key="product"&gt;&lt;/product&gt;
          &lt;/div&gt;
        &lt;/div&gt;
        &lt;div class="shopping-cart"&gt;
          &lt;shopping-cart&gt;&lt;/shopping-cart&gt;
        &lt;/div&gt;
    &lt;/div&gt;
  &lt;/template&gt;
  
  &lt;script&gt;
  
  import ShoppingCart from './components/ShoppingCart.vue'
  import Product from './components/Product.vue'
  
  export default {
    created () {
      // dados mockados
      var dummy = [
        {id: 1, title: 'Name of Product 1', price: 40, image: 'product.png'},
        {id: 2, title: 'Name of Product 2', price: 90, image: 'product.png'},
        {id: 3, title: 'Name of Product 3', price: 10, image: 'product.png'},
        {id: 4, title: 'Name of Product 4', price: 20, image: 'product.png'}
      ];
  
      this.$set('products', dummy)
    },
    data () {
      return {
        products: []
      }
    },
    components: { Product, ShoppingCart }
  }
  
  &lt;/script&gt;
  </code></pre>
  
  <p>What can I do?</p>
  
  <p>I tried a lot of things and still without success =(</p>