vuejs

                                    // file name: index.vue
// structure for vue 2
<template>
  // HTML code 
  // within one element for vue2
</template>
<script>
// js code
export default {
	components: {
      // vue component to use in html
    },
    data () {
      return{
        // all global variables should be declear here
        // this.varName to access variable
        randomVar: 12,
        randomVar2: "Suman"
      }
    },
    computed:{
      // act as variable
      // syntex will be same as function
      // return value will be stored 
    },
    methods: {
      // all global function should be declear here
      // you can use all js syntex here
    },
    mounted (){
      // all other js code to be execuated here (my suggestion)
      // this is a part of "vue-lifecycle"
      // for more details: 
      // https://vuejs.org/v2/guide/instance.html#Lifecycle-Diagram
    }
}
</script>
<style scoped>
// css code
// scoped will enclose all css code within this vue file
</style>

                                    var app2 = new Vue({
  el: '#app-2',
  data: {
    message: 'You loaded this page on ' + new Date().toLocaleString()
  }
})

                                    var app = new Vue({
  el: '#app',
  data: {
    message: 'Hello Vue!'
  }
})

                                    <script src="https://unpkg.com/vue@next"></script> # CDN Version

# NPM or Yarn Version
npm install vue@next

#Vue 3 CLI Installation
yarn global add @vue/cli
# OR
npm install -g @vue/cli

# Vue CLI Create Project
vue create my-project

                                    Best front framework ! :)

                                    <div id="app">
  {{ message }}
</div>

                                    const CounterApp = {
  data() {
    return {
      counter: 0
    }
  },
  mounted() {
    setInterval(() => {
      this.counter++
    }, 1000)
  }
}

                                    <!-- development version, includes helpful console warnings -->
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>

                                    var app = new Vue({
  el: '#app',
  data: {
    message: 'Hello Vue!'
  }
})