question about declaring variables

[BigJimSlade]

Hi, Big Jim here:

Can anyone tell me the difference between these two pieces of code?

***********************
Dim rst as recordset
Set rst = currentdb.OpenRecordset("SELECT * FROM MyTable")
Label.Caption = rst!Field
***********************
Dim rst as Recordset
Dim strField as String
Set rst = currentdb.OpenRecordset("SELECT * FROM MyTable")
strField = rst!Field
Label.Caption = strField
***********************

I notice many programmers do the latter. Is there any reason as to why, and what would this be called? Does it effect performance?

Thanks in advance!

Big Jim

 

[dcx693]

There's no "real" difference in outcome. Just seems like the 2nd version is declaring a variable that, if only used in the context presented, seems extraneous. I almost always go for brevity unless being more wordy will make the program function more obvious.

 

[Mile-O]

Can anyone tell me the difference between these two pieces of code?

Dim rst as recordset
Set rst = currentdb.OpenRecordset("SELECT * FROM MyTable")
Label.Caption = rst!Field
***********************
Dim rst as Recordset
Dim strField as String
Set rst = currentdb.OpenRecordset("SELECT * FROM MyTable")
strField = rst!Field
Label.Caption = strField

It's as dcx said, they do the exact same thing and the variable strField is unnecessary in the second example.

However, you may want to assign a value like that to a variable if you are going to use it repeatedly within the procedure/function. This means you are referencing a cache where the value is held rather than having to refernce the field object in the recrdset object each time.

 

[BigJimSlade]

Big Jim sends his many thanks to both of you!

Mile, I think that is what I was getting at. The variable is stored in cache while the reference to the object is not? So in the end, I guess storing the value in a variable, say looping through a bit of code 1,000 times, would speed things up.

Thanks again!

Big Jim

 

[Mile-O]

So in the end, I guess storing the value in a variable, say looping through a bit of code 1,000 times, would speed things up.

Yes. If the variable is going to be used more than once, and consecutively.