ng-init是給angular執行給定的表達式，初始化變量的值
<!DOCTYPE html>
<html>
<head>
<meta charset='UTF-8'>
<title>ng-init</title>
<script type="text/javascript" src='static/plugins/angular.min.js'></script>
</head>
<body>
<div ng-app='' ng-init='myTest="hello world"'>
{{myTest}}
</div>
</body>
</html>
這樣就初始化了myTest的值，ng-app沒有設值，要是設置的話，就要js啦，要不然就得報錯了