Type.isInstanceOfType Method
Returns a value that indicates whether an object is an instance of a specified class or of one of its derived classes.
var isInstanceOfTypeVar = TypeA.isInstanceOfType(instance);
Parameters
- instance
The object to test.
Return Value
true if instance is an instance of the class; false if instance does not implement the interface, or if it is undefined or null.
Remarks
Use the isInstanceOfType method to determine whether an object is an instance of a specific class.
Example
The following example shows how to use the isInstanceOfType method to determine whether one class is an instance of another class.
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager runat="server" ID="ScriptManager1">
</asp:ScriptManager>
<script type="text/javascript">
// Register classes to test.
Type.registerNamespace('Samples');
Samples.A = function()
{
// Initialize as a base class.
Samples.A.initializeBase(this);
}
Samples.A.registerClass('Samples.A');
Samples.B = function(){}
Samples.B.registerClass('Samples.B', Samples.A);
Samples.C = function(){}
// Register class Samples.C as derived from Samples.A
Samples.C.registerClass('Samples.C');
var test;
// Output: "true".
test = Samples.B.inheritsFrom(Samples.A);
alert(test);
// Output: "false".
test = Samples.C.inheritsFrom(Samples.A);
alert(test);
// Output: "false".
test = Samples.A.isInstanceOfType(Samples.B);
alert(test)
</script>
</form>
</body>
</html>