(一)文本
<span>Message: {{ msg }}</span> //msg會隨著賦值而改變
使用 [v-once 指令]
<span v-once>这个将不会改变: {{ msg }}</span>
例子：
<!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>
<div id="app">
<div v-once>
{{msg}} --app
</div>
</div>
<div id="app2">
<div v-once>
{{msg}} --app2
</div>
</div>
<div id="app3">
<div>
{{msg}} --app3
</div>
</div>
<body>
</body>
<script>
var app = new Vue({
el: '#app',
data: {
msg:''
}
})
app.msg = "999"
var app2 = new Vue({
el: '#app2',
data: {
msg:'666'
}
})
app2.msg = "999"
var app3 = new Vue({
el: '#app3',
data: {
msg:'666'
}
})
app3.msg = "999"
</script>
</html>
index5.png
不管變量初始化後是否賦值
