QTP use Mandatory and assistive Property identifier to uniquely identify the Objects. But in some situation they are not able to uniquely identify the object's properties, and Smart identification also fails to do this work, then only QTP uses Ordinal Identifier.
Ordinal Identifier is always created for every object by QTP but only when Mandatory, Assistive & Smart identification fails to identify object uniquely.
The ordinal identifier assigns the object a numerical value that indicates its order relative to other objects with an otherwise identical description (objects that have the same values for all properties specified in the mandatory and assistive property lists). This ordered value enables QuickTest to create a unique description when the mandatory and assistive properties are not sufficient to do so.
There are three types of ordinal identifiers that QuickTest can use to identify an object:
Index—Indicates the order in which the object appears in the application code relative to other objects with an otherwise identical description.
For Example :
Browser(Browser_Name).Page(Page_Name).link("text:=abc", "index:=0").click
Location—Indicates the order in which the object appears within the parent window, frame, or dialog box relative to other objects with an otherwise identical description.
WebCheckBox("Name:=add/delete", "Location:=0")
Location property value cannot be retreive using GetROProperty.
CreationTime (Browser object only)—Indicates the order in which the browser was opened relative to other open browsers with an otherwise identical description. For more information, see Identifying an Object Using the CreationTime Property.
For Example :
Browser("Name:=Google", "CreationTime:=0")