What's Exit Sub for???

HelloWorld · #1 (**permalink**) 09-30-2007, 09:53 PM

I'm looking at this code and wondering on what's "Exit Sub" is for..

Code:

  If (document.frmExample5a.txtAge.value < 0) Or _

     (document.frmExample5a.txtAge.value > 100) Then

    MsgBox "The age you entered is invalid."

    Exit Sub

  End If

Thanx pals~

Lee · #2 (**permalink**) 10-01-2007, 02:23 AM

Well, if you had the code:

Code:

Sub madeup()
  If (document.frmExample5a.txtAge.value < 0) Or _

     (document.frmExample5a.txtAge.value > 100) Then

    MsgBox "The age you entered is invalid."

    Exit Sub

  End If

'
'
'Information for processing information without checking things are valid.
'
'

End Sub

This i have made up a sub called "madeup", if i wanted to process some information, i may wish to check a value, the if statement does this, when it checks, say i put 101 in the box it will the start showing me the message box, when you click ok in the message box it will continue processing the rest of the code, Exit Sub comes next which means it will Exit the sub rather than it continuing to process the information regardless. (this means where i have put a comment in my code for more statements it wont read there.

Hope that helps, if i have confused you let me know lol.
Lee.

ccoonen · #3 (**permalink**) 10-01-2007, 07:10 AM

Also works for other loops - like if you wanted to be optimized you could do

Code:

For Each DR as DataRow in DataTable
  If DR.ProductID = 34
    MsgBox(DR.ProductName)
    Exit For
  End If
Next

This woulid exit out of the for and save all yoru cpu cycles

HelloWorld · #4 (**permalink**) 10-01-2007, 04:08 PM

so it's kind of break; statement in the loop..? but this one is for a method..? Hey, Sub madeup() isn't a method isn't it? what is it then..? The way we call sub is different than calling a method..? or is it just the same thing? if it's the same, then what's the difference..? XD sorry, tons of question.. lol.. this scripting language is kind of weird to me at first

Lee · #5 (**permalink**) 10-01-2007, 05:04 PM

i used the sub made up as an example, to run the sub you may put "madeup()" inside a buttons sub and it will run the madeup sub...i would say it is like break yes... not sure what you mean for the rest.

chrishirst · #6 (**permalink**) 12-24-2007, 03:47 PM

A "method" is simply a sub or function that is part of a class or an object.

in the same way that a property is simply a variable that is encapsulated in a class.

ccoonen · #7 (**permalink**) 12-24-2007, 09:24 PM

yes, exit [for, sub, etc...] is like break; - it exits out of the local loop

dminder · #8 (**permalink**) 04-24-2008, 09:47 AM

This is my first time posting, happened across the boards when searching for something else. So Hello All!

Anyways, one thing that I find most useful especially when using Exit Sub is that if you have it within a Try...Catch...Finally statement, whatever is in the Finally part of the block will happen regardless of anything else. So, if you wanted to dispose of objects, disconnect from data sources, reset buttons, etc. before you exit the sub/function then you can put this all in the finally block and make sure it is done. However with exit do, while, for - unless the try...catch..finally block is encapsulated within them, the finally will not be triggered right away, it will complete whatever code is beyond them then once it either finishes with the sub/function or hits the exit sub/function command.

This can also be a deficit for the exact same reason, so be sure of what you put in there!!

Good Luck and Happy Coding!!

D

ccoonen · #9 (**permalink**) 04-24-2008, 08:56 PM

Just to keep you in th eloop thats for .NET+ - classic ASP/VBScript doesn't have a try catch

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