How to create instance in Vue.js ?

Last Updated : 06 Nov, 2023

A Vue.js Instance refers to a Vue constructor’s instance in the Vue application. It acts as a container that holds your application’s data and methods. Vue.js implements the Component-Based Architecture that enables the generation of these instances, in order to represent and manage individual components or specific sections of the Vue Application. Each Instance is responsible for performing the specific task that enhances the functionality & interface of the web application. In this article, we will learn how to create a VueJS instance.

Syntax

In the below code snippet, new Vue({…}) initializes a new Vue instance and accepts an object with various options and data properties.

const app = new Vue({
    setup() {
        // Your code here
    }
})

Vue.JS installation

There are the following ways to install Vue.JS:

Directly including CDN file

<script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>

Install it using NPM

Write the following command in the terminal

npm install vue

Approach

To create an instance in VueJS, follow the below steps:

Include the Vue.js library in your HTML file using a script tag.
Create a new Vue instance by calling new Vue({…})
Inside the Vue instance specify the el property and set it to the id of the HTML element you want to bind to.
Use the data property to define the initial data and properties you want to use in your application. You can also add methods inside it.

Example 1: In this example, we will be creating a simple VueJS Instance that renders the Hello GeeksforGeeks text.

HTML

<!DOCTYPE html> 
<html lang="en"> 
  
<head> 
    <meta charset="UTF-8"> 
    <meta name="viewport" 
          content="width=device-width,  
                   initial-scale=1.0"> 
    <script src= 
"https://unpkg.com/vue@3/dist/vue.global.js"> 
    </script> 
</head> 
  
<body> 
    <div id="app">{{ message }}</div> 
  
    <script> 
        const { createApp, ref } = Vue 
  
        createApp({ 
            setup() { 
                const message = ref('Hello GeeksforGeeks') 
                return { 
                    message 
                } 
            } 
        }).mount('#app') 
    </script> 
</body> 
  
</html>

Output:

vuef

Example 2: In this example, we will create a simple VueJS instance representing a counter app.

HTML

<!DOCTYPE html> 
<html lang="en"> 
  
<head> 
    <meta charset="UTF-8"> 
    <meta name="viewport" 
          content="width=device-width,  
                   initial-scale=1.0"> 
    <script src= 
"https://unpkg.com/vue@3/dist/vue.global.js"> 
    </script> 
</head> 
  
<body> 
    <div id="app"> 
        <button @click="incrementCount"> 
            Click Me! 
        </button> 
        <p> 
            Button Clicked {{ count }} 
            times 
        </p> 
    </div> 
  
    <script> 
        const { createApp, ref } = Vue 
        createApp({ 
            setup() { 
                const count = ref(0) 
          
                const incrementCount = () => { 
                    count.value++ 
                } 
          
                return { 
                    count, 
                    incrementCount 
                } 
            } 
        }).mount('#app') 
    </script> 
</body> 
  
</html>