numeric conversion for if check

[Mairaaj Khan]

Hi, i want to check the existence of an integer value in the textbox control with the following code: if (Convert.ToInt16(tbStockTypeId.Text) <= 0) works fine when an intger value is entered. but when i enter 'abc' it raises FormatException "Input string was not in a correct format." Need help for its correction. With Thanx

[J4amieC]

First check if the Text value is numeric before trying to convert it. This can be done with a RegEx, or Char.IsNumeric Current blacklist svmilky - Extremely rude | FeRtoll - Rude personal emails | ironstrike1 - Rude & Obnoxious behaviour

[V 0]

try{ int stocktype = Convert.ToInt16(tbStockTypeId.Text);   if(stocktype <= 0) {     //do stuff   } } catch(FormatException fexc){   Messagebox(tbStockTypeId.Text + "Is not a number"); } Coulda, woulda, shoulda doesn't matter if you don't. [MODIFIED]In this 32 bit world, use ToInt32 unless you have little memory.[/MODIFIED] :beer:
:jig: -- modified at 10:53 Friday 26th May, 2006

[J4amieC]

Although that would work absolutely fine, its generally considered bad practice to control program flow with exceptions. Exceptions for exceptional behaviour - the user making an invalid entry is not exceptional, it is expected! Current blacklist svmilky - Extremely rude | FeRtoll - Rude personal emails | ironstrike1 - Rude & Obnoxious behaviour

[V 0]

J4amieC wrote:

the user making an invalid entry is not exceptional, it is expected

He he , I agree on this, but I don't understand why using try/catch is bad practice? Coulda, woulda, shoulda doesn't matter if you don't. :beer:
    :jig:

[J4amieC]

I guess because throwing exceptions is just more resource intensive, its a lot quicker to first check if the value is valid. Current blacklist svmilky - Extremely rude | FeRtoll - Rude personal emails | ironstrike1 - Rude & Obnoxious behaviour

[V 0]

mja, sounds reasonable. tnx. Coulda, woulda, shoulda doesn't matter if you don't. :beer:
    :jig:

[Robin Panther]

If you are using .NET 2.0 - why not use Int32.TryParse()? short outint; if (!Int16.TryParse(tbStockTypeId.Text, out outint)) { throw new ArgumentException("Argument is not integer", "tbStockTypeId"); } //use outint ____________________________________________ Robin Panther http://www.robinland.com

[Mairaaj Khan]

thanks for reply! J4amieC Char.IsNumeric is fine for a character, while i'm working with textbox string. uroojkhan

[Mairaaj Khan]

thanks V! about Exceptions agree with J4amieC. Do remember (for Int16 and Int32) What u required is more important than what u have! Regards, uroojkhan

[Mairaaj Khan]

with a lot of thanks Robin Panther! its solved my problem. Do remember (for Int16 and Int32) What u required is more important than what u have! Regards, uroojkhan