QTP - Argument types

Arguments can be passed as

·         Pass ByValue

·         Pass ByReference

Represented as

        ByRef

        ByVal

Description about ByVal:
Indicates that the argument is passed by value.
Description about ByRef :
Indicates that the argument is passed by reference.

Note:By default all arguments are 'ByRef'.

   

·         ByRef explains that the value which is assigned to the variable within the function is permanent and we can use that value outside of that function too

·         It references the function and corresponding value assigned within the function

·         ByVal explains that the value which is assigned to the variable within the function is temporary and we can use that value only within that function.

·         It references the value assigned outside of the function

Examples:

' Arguments passing to functions

' Pass ByRef

' Pass ByVal

'‘************************************************************************

' Function name   : Demo_PassingArgs1

' Variables    : num1 , num2  --.> both are declared as ByRef(BY DEFAULT)

' Passed  arguments a,b       :  a=10, b=20

' Returning values : a=100, b=200 ( a=num1, b=num2 ; both values are passed as ByRef)

'‘************************************************************************

a=10

b=20

msgbox Demo_PassingArgs1(a,b)

msgbox a

msgbox b

Function Demo_PassingArgs1(num1,num2)

   num1=100

   num2=200

    Demo_PassingArgs1=num1+num2

End Function

'‘***********************************************************************

' Function name   :  Demo_PassingArgs2

' Variables     : num1 , num2  --.> both are declared as ByRef 

'  Passed  arguements a,b     : a=10, b=20

' Returing values : a=100, b=200 ( a=num1, b=num2 ; both values are passed as ByRef)

'‘***********************************************************************

a=10

b=20

msgbox Demo_PassingArgs2(a,b)

msgbox a

msgbox b

Function Demo_PassingArgs2(ByRef num1,ByRef num2)

   num1=100

   num2=200

    Demo_PassingArgs2=num1+num2

End Function

'‘************************************************************************

Function name  :  Demo_PassingArgs3

'Variables: num1,num2  --> both are declared as ByVal (declared in function)

'Passed  arguements a,b    : a=10, b=20

'Returing values : a=10, b=20 ( a=num1, b=num2 ; both values are passed as ByVal)

'‘***********************************************************************

a=10

b=20

msgbox Demo_PassingArgs3(a,b)

msgbox a

msgbox b

Function Demo_PassingArgs3(ByVal num1,ByVal num2)

   num1=100

   num2=200

    Demo_PassingArgs3=num1+num2

End Function

'‘************************************************************************

' Function name   :  Demo_PassingArgs4

'Variables: num1,num2 -->

'num1  is declared as ByRef and num2 is declared as ByVal

'Passed  arguements a,b    : a=10, b=20

'Returing values :  

'a=100, b=20( a=num1 (num1 is ByRef) , b=num2  ( num2 is ByVal)

'‘************************************************************************

a=10

b=20

msgbox Demo_PassingArgs4(a,b)

msgbox a

msgbox b

Function Demo_PassingArgs4(ByRef num1,ByVal num2)

   num1=100

   num2=200

    Demo_PassingArgs4=num1+num2

End Function