Vue3写法
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <script src="https://unpkg.com/vue@3"></script> </head> <body> <div id="app"> <h3>count的值为:{{state.count}}</h3> <button v-on:click="addCount">+1</button> <button @click="state.count+=1">+1</button> <button v-on:click="negativeCount">-1</button> </div> <!-- <script> const vm ={ data:function(){ return { count:0 } }, methods:{ addCount(){ this.count+=1 } } } Vue.createApp(vm).mount('#app') </script> --> <script> const {createApp,reactive} = Vue; createApp({ setup(){ const state = reactive({ count:0 }) const addCount = ()=>{ state.count+=1 } const negativeCount = ()=>{ state.count-=1 } return { state, addCount, negativeCount } } }).mount('#app'); </script> </body> </html>