<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<div id="app">
<input type="text" name="" id="" v-model:value="n1">
<select name="" id="" v-model:value="opt">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">*</option>
<option value="/">/</option>
</select>
<input type="text" v-model:value="n2">
<input type="button" value="=" @click="calc">
<input type="text" v-model="result">
</div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
<script>
var app= new Vue({
el:'#app',
data:{
n1:0,
n2:0,
result:0,
opt:'+'
},
methods:{
calc(){
// var codeStr='prseInt(this.n1)'+this.opt+'prseInt(this.n2)'
// this.result=eval(codeStr)
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>