Getting Started with Knockout.js for .NET Developers

Computed observables

In this section, we will discuss a special way to create complex properties that depend on our existing observable properties. The standard approach in the Knockout.js library is computed observables. We will consider these kinds of properties with a simple example.

Using a computed observable

Let's add two base observable properties in the Model (the person object) and ViewModel (the personViewModel object): firstName and lastName (PersonalPage-Computed1.html). The initial values of these properties will be John and Doe, respectively.

The Model will be as follows:

var person = {
  firstName: "John",
  lastName: "Doe"
};

The ViewModel will be as follows:

var personViewModel = function() { var self = this; self.firstName = ko.observable(person.firstName); ...