Knockout Javascript example

knockout.js

<p>First name: <input data-bind="value: firstName" /></p>
<p>Last name: <input data-bind="value: lastName" /></p>
<h2>Hello, <span data-bind="text: fullName"> </span>!</h2>

 // data model
var ViewModel = function(first, last) {
    this.firstName = ko.observable(first);
    this.lastName = ko.observable(last);
 
    this.fullName = ko.pureComputed(function() {
        // Knockout tracks dependencies automatically. It knows that fullName depends on firstName and lastName, because these get called when evaluating fullName.
        return this.firstName() + " " + this.lastName();
    }, this);
};
 
ko.applyBindings(new ViewModel("Planet", "Earth"));