Global variables

ps124 · April 4th, 2004, 08:46 PM

can anyone tell me how to assign a value in a sub routine into a global variable? an example of my code is shown below...

Dim Number1 as Integer
Dim RAnswer as Integer

Sub Start_Click

'other coding goes here..................

Number1 = objDataReader("QNo")
RAnswer = objDataReader("QAns")

End sub

i want to assign the two numbers retreived from the datareader into the global variables Number1 and RAnswer. can anyone also tell me if i have declared the global variables correctly. Thanx

melvik · April 4th, 2004, 11:11 PM

http://p2p.wrox.com/topic.asp?TOPIC_ID=2064
u can find ur answer there as I did!!!

Always:),
Hovik Melkomian.

planoie · April 5th, 2004, 06:35 AM

That looks perfectly fine to me.

One bit of advice, most standards recommend prefixing globals with something to indicate they are global. Often you will see something like this...

Dim _objSomeObject As Object
Dim _nSomeInt As Integer

The _ indicates it's global. Also, try to limit use of global variables. You can often avoid them with the right use of function parameters or return values/objects, particularly now that .net is fully object oriented.

Peter
------------------------------------------------------
Work smarter, not harder.

ps124 · April 5th, 2004, 10:12 AM

hi,
thanx for the guidance ebut i have realised what the problem is now. in my first subroutine, i am passign the values into the global variable but when i am calling the same variable in a second subroutine, expecting it to hold the value from the first subroutine, it doesn't. it only holds the default values. how can i get it to hold the value from the first subroutine so i can use it in the second. i have been told i can call the first subroutine in the second but can anyone tell me if this is the way??? thanx

stu9820 · April 5th, 2004, 12:52 PM

Use a function to return what you need.

Function blahBeDeBlah as String(Whatever)
do something
Return variable_name
End Function

melvik · April 5th, 2004, 11:29 PM

I got my lesson & let me to tell u that too:D
ur calss will be as:

Code:

    public class Const
    {
        private static string connectionString = "ur value";
        public static string DabirConn
        {
            set
            {
                connectionString = value;
            }
            get
            {
                return connectionString;
            }
        }
    }

Then to set & get the value
use

Code:

[u]set:</u>
Class_Name.DabirConn = "new value";
[u]get:</u>
a = Class_Name.DabirConn;

This is what I did & works fine.
HTH.

Always:),
Hovik Melkomian.

planoie · April 6th, 2004, 02:48 PM

ps124-

Simple data types, like Integers, are "value" types. The variable holds a value. (The other type is a reference type). Typically, when you pass such a variable to a function, you pass the variable's value. In essense, what you are doing in a function declaration is declaring a local scope variable for use inside the function. As a result, any modification to that variable will not be seen outside the function. As such, passing a global variable into a function kind of defeats the purpose of having a global variable. All you need to do is use the global variable inside the function and its value will be persisted between function calls. This way, a value assigned to the global variable in one function will be seen by the second function.

Peter
------------------------------------------------------
Work smarter, not harder.