pluck
描述 (Description)
它从集合中的每个模型中检索属性。
语法 (Syntax)
collection.pluck(attribute)
参数 (Parameters)
attribute - 它表示已定义模型的属性。
例子 (Example)
<!DOCTYPE html>
<html>
<head>
<title>Collection 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>
</head>
<body>
<script type = "text/javascript">
var LangNames = Backbone.Model; //'LangNames' is a model name
var langauges = new Backbone.Collection; //'langauges' is a collection instance
//The collection instance used with comparator() method to compare the items and display them
//in descending order
langauges.comparator = function(value1, value2) {
//The comparator returns -1, when the first model should display before the second model
if (value1.get('name') > value2.get('name')) return -1;
//It returns -1, when the first model should display after the second model
if (value2.get('name') > value1.get('name')) return 1;
return 0;
};
langauges.add(new LangNames({name: "Java"}));
langauges.add(new LangNames({name: "PHP"}));
langauges.add(new LangNames({name: "HTML"}));
//The pluck() method returns an attribute, by using "name" attribute from the model in the collection
document.write("Attributes returned on pluck('name'): ",langauges.pluck('name'));
</script>
</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pluck.htm文件中。
在浏览器中打开此HTML文件。
