propsData 不是和属性有关，他用在全局扩展时进行传递数据。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<script type="text/javascript" src="../assets/js/vue.js"></script>
<title>PropsData Option Demo</title>
</head>
<body>
<h1>PropsData Option Demo</h1>
<hr>
<header></header>
<script type="text/javascript">
var header_a = Vue.extend({
template:`<p>{{message}}</p>`,
data:function(){
return {
message:‘Hello,I am Header‘
}
}
});
new header_a().$mount(‘header‘);
</script>
</body>
</html>
var header_a = Vue.extend({ template:`<p>{{message}}-{{a}}</p>`, data:function(){ return { message:‘Hello,I am Header‘ } }, props:[‘a‘] }); new header_a({propsData:{a:1}}).$mount(‘header‘);
原文：https://www.cnblogs.com/xiaofandegeng/p/9029155.html