by Sai gowtham

How to declare a global variable in Vue.js

In this tutorial, we are going to learn about how to declare a global variable in vuejs with the help of an example.

Sometimes we need to access a particular data throughout our app components in such cases we can create a global variable in vue.js by using this syntax.

Vue.prototype.$variablename

where $ is a naming convention to declare the global variables.

Declaring a global variable

In this example, we are declaring a $axios global variable which helps us to use the axios object in our components to send the http requests.

Open you main.js file and add the below code.

main.js
import Vue from 'vue'
import App from './App.vue'
import axios from 'axios'

// global variable
Vue.prototype.$axios = axios

new Vue({
  render: h => h(App),
}).$mount('#app')

Accessing global variable

We can access the global variable from any component instance by using this.$variablename.

App.vue
<template>
  <div id="app">
    <ul v-for="user in users" :key="user.id">
      <li>{{user.id}}</li>
      <li>{{user.name}}</li>
    </ul>
  </div>
</template>

<script>
export default {
  data: function() {
    return {
      users: []
    };
  },
  created: function() {
    this.$axios.get("https://jsonplaceholder.typicode.com/users")    .then(res => {
      this.users = res.data;
    });
  }
};
</script>

output:

vue-global-variable-example

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