what is variables and why we declare variables in vba

[vksharma00001]

Hi Experts

Can anyone suggest me that what is variables and why we declare variables in vba ?

Thanks in advance
Vijay K Sharma

 

[Michael M]

This is a pretty good description of Variables and declaring them....


Declaring Variables

 

[WarPigl3t]

It's easier to explain the purpose of a variable than what a variable is. A variable is an object. You see how that doesn't really tell you anything about what a variable is? Now the purpose of a variable is to hold a value. So lets say you have a variable called myVariable. Now lets say you have a line of code that says myVariable = 2. So now it is equal to 2. Think about why you would want to use a variable that is equal to 2 rather than just using the number 2 in your code. One example is if you are creating a loop. Each time the code runs through the loop, it needs to add 1 to the variable. This is how it keeps track of how many times it runs through the loop. Here's an example.

myVariable = 1
Do Until myVariable = 5
'some code
myVariable = myVariable + 1
Loop

Looking at the code above, it will contine to add 1 to myVariable each time it goes through the loop. Once myVariable equals 6, it is greater than 5 so it exists the loop. Try accomplishing the same thing by unsing a number instead of a variable. You can't. This is only one reason you would use a variable. Now for your other question, why do you declare a variable. Well I don't declare variables. This is an example of declaring a variable...
Dim myVariable as Integer
I never do this. VB automatically assumes a declaration based on what the variable equals. So I don't like to make my code longer than it has to by making lines and lines of declaration code. There are instances that you have to declare a variable such as when you create an array variable. In this case, I just wait for VB to give me a declaration error message when I run the code before I make declare the variable. I don't like to do more work than I have to. But some programmers do things the right way. You really should declare all of your variables. The reason is because you may be using more resources than needed. For example lets say myVariable = 2 and I didn't declare it as an Integer because I didn't declare it at all. VB will assume it is a Double. Double uses up way more system resources than Integer. Honestly I wouldn't care less, but if you are creating code for a very large program, it could slow the system down dramatically. So in that instance, I would delare my variables.

 

[vksharma00001]

Thanks to both of you for solving my query.

 

[Jon von der Heyden]

It's easier to explain the purpose of a variable than what a variable is. A variable is an object. You see how that doesn't really tell you anything about what a variable is? Now the purpose of a variable is to hold a value. So lets say you have a variable called myVariable. Now lets say you have a line of code that says myVariable = 2. So now it is equal to 2. Think about why you would want to use a variable that is equal to 2 rather than just using the number 2 in your code. One example is if you are creating a loop. Each time the code runs through the loop, it needs to add 1 to the variable. This is how it keeps track of how many times it runs through the loop. Here's an example.

myVariable = 1
Do Until myVariable = 5
'some code
myVariable = myVariable + 1
Loop

Looking at the code above, it will contine to add 1 to myVariable each time it goes through the loop. Once myVariable equals 6, it is greater than 5 so it exists the loop. Try accomplishing the same thing by unsing a number instead of a variable. You can't. This is only one reason you would use a variable. Now for your other question, why do you declare a variable. Well I don't declare variables. This is an example of declaring a variable...
Dim myVariable as Integer
I never do this. VB automatically assumes a declaration based on what the variable equals. So I don't like to make my code longer than it has to by making lines and lines of declaration code. There are instances that you have to declare a variable such as when you create an array variable. In this case, I just wait for VB to give me a declaration error message when I run the code before I make declare the variable. I don't like to do more work than I have to. But some programmers do things the right way. You really should declare all of your variables. The reason is because you may be using more resources than needed. For example lets say myVariable = 2 and I didn't declare it as an Integer because I didn't declare it at all. VB will assume it is a Double. Double uses up way more system resources than Integer. Honestly I wouldn't care less, but if you are creating code for a very large program, it could slow the system down dramatically. So in that instance, I would delare my variables.

I mean the following in the nicest possible way... I would elaborate but I don't have the time or energy now but for starters I just don't want anyone to get bad information and not know about it... The topic of variables is fundamental to good programming.

@WarPiglet: I'm afraid so very many of your statements above are totally wrong. Even down to the very foundation of what variables are and when/why we should use them and why we should always declare them. I encourage you to research the topic. The article Michael referred to should help improve your knowledge of variables considerably.

@Vijay: Please stick with the article referred to by Michael.

I also suggest you read this article and all associates sub-articles.

 

[hiker95]

vksharma00001,

See the following link for more information:

Using Variables in Excel VBA Macro Code
Excel VBA Variables. Using Variables in Excel VBA Macro Code

 

[vksharma00001]

Thank you so much Jon and Hiker95 for providing such a valuable understanding on this topic. Really thankful to all of you.

 

[hiker95]

vksharma00001,

Thanks for the feedback.

You are very welcome. Glad we could help.

And, come back anytime.


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