What happens in this situation...

[mark smit]

Hi guys,


I was hoping somebody could explain to me what exactly happens when you have a global variable, we'll call it SESSION, and you use the same name in a functions parameter list.

type CSession
    m_Number as long
end type

global Session as CSession

function OpenSession(Session as CSession) as long
    Session.m_Number = 2048
end function

Is this even legal or is the compiler just missing this?


does the parameter act as a local variable inside the function and not even see the global variable?

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Cheers

[This message has been edited by mark smit (edited February 06, 2001).]

[mark smit]

Here is a better example of what I mean...

rem test
rem
#compile exe


type CPerson
    Age as long
    FirstName as asciiz * 64
    LastName as asciiz * 64
end type


global Person as CPerson

function MakePerson(Person as CPerson,byval Age as long,byval FirstName as string,byval LastName as string) as long
    Person.Age = Age
    Person.FirstName = FirstName
    Person.LastName = LastName
end function


function pbmain as long
    dim Other as CPerson
    
    MakePerson Person,38,"Bill","Gates"
    MakePerson Other,32,"John","Carmack"
    
    msgbox Person.FirstName & $CRLF & Other.FirstName
end function

The variable "Person" is a global and also used as a parameter in the function MakePerson. It seems to work but I'm not clear on why.

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Cheers

[Don Dickinson]

It works because you're passing Person as a parameter. This effectively makes Person a local variable. Local varaibles override globals when they are named the same.
--Don


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www.basicguru.com/dickinson

[Borje Hagsten]

Be careful though. Trying to put ID software's John Carmack and
Bill Gates in same room may result in some real serious GPF's..


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[mark smit]

HeHeHe!!

I was wondering if anybody else was gonna notice those names Borje

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Cheers