v-model用于数据的双向绑定。bug不少，凑合看吧，主要是练习v-model。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
</head>
<body>
<div id="app">
<!-- v-model 双向绑定数据 -->
<input type="text" v-model="n1"> <select v-model="opt">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select> <input type="text" v-model="n2"> <!-- @ 用于事件绑定 -->
<input type="button" value="=" @click="cal"> <input type="text" v-model="result">
</div>
</body>
<script>
let vm = new Vue({
el: '#app',
data: {
n1: 0,
n2: 0,
result: 0,
opt: '+'
},
methods: {
cal(){
switch(this.opt){
case '+':
this.result = parseInt(this.n1) + parseInt(this.n2)
break
case '-':
this.result = parseInt(this.n1) - parseInt(this.n2)
break
case '*':
this.result = parseInt(this.n1) * parseInt(this.n2)
break
case '/':
this.result = parseInt(this.n1) / parseInt(this.n2)
break
}
}
}
})
</script>
</html>