where
优质
小牛编辑
133浏览
2023-12-01
描述 (Description)
它用于通过使用集合中的匹配属性来显示模型。
语法 (Syntax)
collection.where(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">
//'Player' is a model name
Player = Backbone.Model.extend ({
name: ""
});
//The 'PlayersCollection' is an instance of the collection
PlayersCollection = Backbone.Collection.extend ({
model: Player //The model 'Player' is specified by overriding the "model" property of the collection
});
var player1 = new Player({ name: "Dravid" });
var player2 = new Player({ name: "Raina"});
var player3 = new Player({ name: "Jadeja"});
var mycollection = new PlayersCollection();
//The 'player1','player2' and 'player3' are 3 instances added to the collection by using 'mycollection' instance
mycollection.add(player1);
mycollection.add(player2);
mycollection.add(player3);
//The where() method returns the model, which contains the name with "Raina" in the collection
var myteam = mycollection.where({ name: 'Raina' });
document.write("Total numbers of items that matches given attribute are:",
+myteam.length);
</script>
</body>
</html>