Introduction:

This document is useful for creating functions and sub-procedures in keyword driven QTP Testing.This illustrates the basic differences between the Fuctions and Sub-Procedures.It also explains how to associate procedures to QTP Tests.

Difference between Functions and Sub Procedures:

In QTP there are 2 types of procedures:

· Sub Procedures

· Function Procedures

Sub Procedure:

A sub procedure is a series of VBScript statements, enclosed by Sub and End Sub statements which perform actions but do not return a value. A sub procedure can take arguments. If a sub procedure doesn’t receive any arguments, its Sub statement must include an empty parenthesis ().

Sub ConvertTemp()

temp = InputBox("Please enter the temperature in degrees F.", 1)

MsgBox "The temperature is "& Celsius(temp) & " degrees C."

End Sub

Function Procedure:

A function procedure is a series of VBScript statements enclosed by the Function and End Function statements. A function procedure is similar to a sub procedure but it can return value to the calling function. A function procedure can take arguments (constants, variables or expressions that are passed to it by a calling procedure). If a function procedure has no arguments, it Function statement must include an empty set of parenthesis. A function returns a value by assigning a value to its name in one or more statements of the procedure. Since VBScript has only one base data type, a function always returns a variant.

Function Celsius(fDegrees)

Celsius = (fDegrees - 32) * 5 / 9

End Function

So to get data out of a procedure a Function is used. Since Function can return a value while a Sub cannot.

The following example shows two calls to the procedure. One uses the Call method, while the other doesn’t.

Call ConvertTemp()

ConvertTemp

Note: The Parentheses are omitted when the Call statement is not being used.