has
描述 (Description)
如果将属性设置为非null或非undefined值，则此方法返回true 。
语法 (Syntax)
model.has(attribute)
参数 (Parameters)
attribute - 属性定义已创建模型的属性。
例子 (Example)
<!DOCTYPE html>
<html>
<head>
<title> Model Example</title>
<script src = "https://code.jquery.com/jquery-2.1.3.min.js"
type = "text/javascript"></script>
<script src = "https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.2/underscore-min.js"
type = "text/javascript"></script>
<script src = "https://cdnjs.cloudflare.com/ajax/libs/backbone.js/1.1.2/backbone-min.js"
type = "text/javascript"></script>
<script type = "text/javascript">
var Company = Backbone.Model.extend();
var company = new Company();
company.set({ Name: "IoWiki", comp_site:"www.iowiki.com"});
if(company.has('comp_site')) {
document.write("The model Company has site: True");
} else {
document.write("The model Company has site: False");
}
</script>
</head>
<body></body>
</html>
输出 (Output)
让我们执行以下步骤来查看上述代码的工作原理 -
将以上代码保存在has.htm文件中。
在浏览器中打开此HTML文件。
