Object.getType Function
Returns the type of a specified object instance.
var typeVar = Object.getType(instance);
Arguments
Term |
Definition |
|---|---|
instance |
The object to return the type for. |
Returns
A type instance that represents the run-time object of instance.
Exceptions
Exception type |
Condition |
|---|---|
(Debug) instance is undefined. |
|
(Debug) instance is null. |
Remarks
Use the getType function to get a new type instance that represents the run-time type of an object.
Example
The following example shows how to use the getType function to create a new type instance that represents the run-time type of an object. It then displays information based on the object type.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="https://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Samples</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager runat="server" ID="ScriptManager1">
</asp:ScriptManager>
<script type="text/javascript">
Type.registerNamespace('Samples');
// Define and register a Samples.Rectangle class.
Samples.Rectangle = function(width, height)
{
this._width = width;
this._height = height;
}
Samples.Rectangle.prototype.getWidth = function() {
return (this._width === undefined) ? null : this._width;
}
Samples.Rectangle.prototype.getHeight = function() {
return (this._width === undefined) ? null : this._height;
}
Samples.Rectangle.registerClass('Samples.Rectangle');
// Define and register a Samples.Square class.
Samples.Square = function(length)
{
this._length = length;
}
Samples.Square.prototype.getLength = function() {
return (this._length === undefined) ? null : this._length;
}
Samples.Square.prototype.setLength = function(length) {
this._length = length;
}
Samples.Square.registerClass('Samples.Square');
// Create instances of Square and Rectangle and discover their types.
Samples.testObjectReflection = function()
{
var width = 200;
var height = 100;
var a = new Samples.Rectangle(width, height);
var length = 50;
var b = new Samples.Square(length);
var name = Object.getTypeName(a);
// Output "The type name of object a is: Samples.Rectangle"
alert("The type name of object a is: " + name);
var isSquare = Samples.Rectangle.isInstanceOfType(b)
// Output "Object b is an instance of type Square: false"
alert("Object b is an instance of type Square: " + isSquare);
var c = Object.getType(b);
name = Object.getTypeName(c);
// Output "The type name of object c is: Function"
alert("The type name of object c is: " + name);
var isSquare = Samples.Square.isInstanceOfType(c);
if (isSquare)
{
var newLength = a.getWidth();
c.setLength(newLength);
alert("Object c is a Square with a length of: " + c.getLength());
}
}
// Run the sample.
Samples.testObjectReflection();
</script>
</form>
</body>
</html>