class.md

title
Class

kendo.Class

The base class of most Kendo objects. Provides simple inheritance support.

Fields

fn Object

An alias to the prototype of the class. Often used to call methods of the base class.

Example - use the prototype to call base methods

<script>
// Create a base class
var Animal = kendo.Class.extend({
    // The `init` method will be called when a new instance is created
    init: function(legs) {
       this.legs = legs;
    }
});

// Inherit from that class

var Bird = Animal.extend({
    init: function() {
        // Use the `fn` field to call the `init` method of the base class (Animal)
        Animal.fn.init.call(this, 2);
    }
});

var birdie = new Bird();

console.log(birdie.legs); // outputs 2
</script>

Class methods

extend

Extends an existing class with new methods.

Returns

Object a new class which inherits the base methods.

Parameters

prototype Object

A key/value pair of all methods that the new class will have.

Example - inheritance

<script>
var Animal = kendo.Class.extend({
    move: function() {
        console.log("Animal.move()");
    }
});

var Bird = Animal.extend({
   move: function() {
        Animal.fn.move.call(this);

        console.log("Fly");
   }
});

var Cat = Animal.extend({
   move: function() {
        Animal.fn.move.call(this);

        console.log("Sneak");
   }
});

var tweety = new Bird();

tweety.move(); // outputs "Animal.move()" then "Fly"

var sylvester = new Cat();

sylvester.move(); // outputs "Animal.move()" then "Sneak"

console.log(tweety instanceof Bird); // outputs "true" because tweety is an instanfe of Bird

console.log(tweety instanceof Animal); // outputs "true" because Animal is the base class of Bird

console.log(tweety instanceof Cat); // outputs "false" because tweety is not an instance of Cat
</script>