The Backbone.JS At() collection method retrieves a model from a collection by using a specified index.
Syntax:
index()
Parameters:
index: This parameter is used to specify the index position for the retrieval of the model from a collection.
Example:
<title>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 Student = Backbone.Model.extend({
defaults: {
id:"",
name: ""
} });
var StudentCollection = Backbone.Collection.extend({
model: Student
});
var Student1 = new Student({id:1, name: "Tom" });
var Student2 = new Student({id:2, name: "Jerry"});
var X = new StudentCollection();
X.add([Student1,Student2]);
document.write('<b>Old Students List:</b> ' + JSON.stringify(X.toJSON()));
var Student3 = new Student({id:3, name: "Bruno" });
X.add(Student3,{at:2});
document.write('<br><b>New Students List:</b> ' + JSON.stringify(X.toJSON()));
</script><b>Old Students List:</b> [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]<br><b>New Students List:</b> [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
<title>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 Student = Backbone.Model.extend({
defaults: {
id:"",
name: ""
} });
var StudentCollection = Backbone.Collection.extend({
model: Student
});
var Student1 = new Student({id:1, name: "Tom" });
var Student2 = new Student({id:2, name: "Jerry"});
var X = new StudentCollection();
X.add([Student1,Student2]);
document.write('<b>Old Students List:</b> ' + JSON.stringify(X.toJSON()));
var Student3 = new Student({id:3, name: "Bruno" });
X.add(Student3,{at:2});
document.write('<br><b>New Students List:</b> ' + JSON.stringify(X.toJSON()));
</script><b>Old Students List:</b> [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]<br><b>New Students List:</b> [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
Example Old Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]
New Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
Output:
Old Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]
New Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
Old Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]
New Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
Old Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"}]
New Students List: [{"id":1,"name":"Tom"},{"id":2,"name":"Jerry"},{"id":3,"name":"Bruno"}]
Explanation:
In the above example, the model ‘Student3’ is added at 2nd index of the collection.