[Vuejs]-Displaying data in Vuejs Template a Multi data in one single cell

“notifications” is not a valid object. First validate the object, then iterate like below:

<div v-for="notification in Object.keys(notifications)">
   {{ notifications[notification] }}
</div>

One more thing, your “data” in “notifications” object is a string. So you can’t access “user_id” key by dot notation from this.
check this fiddle for more clarification.