abstract：<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Vue两个整数案例</title> <script src="vue.js">
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Vue两个整数案例</title>
<script src="vue.js"></script>
</head>
<body>
<div id="app">
<input type="text" v-model="num1">
<input type="text" v-model="num2">
<select v-model="sum">
<option value="+">+</option>
<option value="-">-</option>
<option value="*">x</option>
<option value="/">÷</option>
<option value="%">%</option>
</select>
<p>{{num1}} {{sum}} {{num2}} = {{num3}}</p>
</div>
</body>
</html>
<script>
let vm = new Vue({
el: '#app',
data: {
num1: '',
num2: '',
num3: '',
sum: '',
},
watch: {
sum: function(value){
switch(value){
case '+':
this.num3 = parseInt(this.num1) + parseInt(this.num2);
break;
case '-':
this.num3 = parseInt(this.num1) - parseInt(this.num2);
break;
case '*':
this.num3 = parseInt(this.num1) * parseInt(this.num2);
break;
case '/':
this.num3 = parseInt(this.num1) / parseInt(this.num2);
break;
case '%':
this.num3 = parseInt(this.num1) % parseInt(this.num2);
break;
}
}
}
});
</script>
Correcting teacher：天蓬老师Correction time：2019-03-28 17:08:35
Teacher's summary：双向绑定是基于事件监听的, 这与mvvm模型息息相关