As I can determining if string can be turned to a numerico value?

[Daniel R. Rossnagel]

As I can determining if string can be turned to a numerico value?, since to
contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[John Murray]

In the 2.0 framework, look for the TryParse method .... otherwise, the
easiest approach (not necessarily the most speedy) is to wrap the
convert in an exception handler.
Daniel R. Rossnagel wrote:

As I can determining if string can be turned to a numerico value?, since to
contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Denis Dougall]

Using Regular expressions is the most cost effective way.

private static Regex _isNumber = new Regex(@"^\d+$") ;

public static bool IsInteger(strin g theValue)
{
Match m = _isNumber.Match (theValue);
return m.Success;
} //IsInteger

OR
If you dont find that to your taste use this

public bool IsNumeric(strin g s)
{
try {
Int32.Parse(s);
}
catch {
return false;
}
return true;
}
HTH,

Denis
"Daniel R. Rossnagel" <dr*********@ho tmail.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

As I can determining if string can be turned to a numerico value?, since to contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Gabriel Magana]

Just one note: Exceptions are very time consuming to handle, they should not
be a part of normal execution...

Not that I can claim to never have done it, but it really is not solid
design to allow exceptions to trigger as part of normal system function...

"Daniel R. Rossnagel" <dr*********@ho tmail.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

As I can determining if string can be turned to a numerico value?, since
to contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Michael Bray]

Regular expressions are certainly not the most cost effective. In fact
its just wrong - your regex doesn't account for integers that are too
large, nor does it account for negative numbers.

Under .NET 2.0, you can use int.TryParse(.. .). Under 1.1, the try/catch
with int.Parse is better than the regex method.

-mdb
"Denis Dougall" <De***********@ here.there.com> wrote in
news:er******** ******@tk2msftn gp13.phx.gbl:

Using Regular expressions is the most cost effective way.

private static Regex _isNumber = new Regex(@"^\d+$") ;

public static bool IsInteger(strin g theValue)
{
Match m = _isNumber.Match (theValue);
return m.Success;
} //IsInteger

OR
If you dont find that to your taste use this

public bool IsNumeric(strin g s)
{
try {
Int32.Parse(s);
}
catch {
return false;
}
return true;
}
HTH,

Denis
"Daniel R. Rossnagel" <dr*********@ho tmail.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

As I can determining if string can be turned to a numerico value?,
since

to

contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Denis Dougall]

Well then what about "reference Microsoft.Visua lBasic.dll", and use
IsNumeric. What performance impact would that have?

Denis
"Gabriel Magana" <no***@nospam.c om> wrote in message
news:uv******** ******@TK2MSFTN GP12.phx.gbl...

Just one note: Exceptions are very time consuming to handle, they should not be a part of normal execution...

Not that I can claim to never have done it, but it really is not solid
design to allow exceptions to trigger as part of normal system function...

"Daniel R. Rossnagel" <dr*********@ho tmail.com> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

As I can determining if string can be turned to a numerico value?, since
to contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Gabriel Magana]

> Well then what about "reference Microsoft.Visua lBasic.dll", and use

IsNumeric. What performance impact would that have?

None... That'd be a good thing to do.

[Jon Skeet [C# MVP]]

Gabriel Magana wrote:

Well then what about "reference Microsoft.Visua lBasic.dll", and use
IsNumeric. What performance impact would that have?

None... That'd be a good thing to do.

Interesting that you think that would be a good thing to do, but using
exceptions would be too expensive.

I looked at this a while back - search for IsNumeric and
sk***@pobox.com on google groups and you'll find the code (I believe).
Here are the results I got (this was for integers, btw):

JustException: 00:01:15.798993 6
HardCodedCheck: 00:00:00.701008 0
DoubleTryParse: 00:00:40.838723 2
Regex: 00:00:43.041891 2
IsNumeric: 00:01:06.906206 4

So using IsNumeric isn't really that much cheaper than using
exceptions. Note the raw speed of the hard-coded check though... one in
the eye for those who say that regular expressions are always the
fastest way to analyse text ;)

Jon

[Daniel R. Rossnagel]

Thanks, were of much utility
"John Murray" <jm*****@pluck. com> escribió en el mensaje
news:OU******** ********@TK2MSF TNGP15.phx.gbl. ..

In the 2.0 framework, look for the TryParse method .... otherwise, the
easiest approach (not necessarily the most speedy) is to wrap the convert
in an exception handler.
Daniel R. Rossnagel wrote:

As I can determining if string can be turned to a numerico value?, since
to contain alfanumeric data it returns an error to me.
as I can avoid the following error?

String str="123";
int valInt = Convert.ToInt32 (str); //OK
String str="StringXX"
int valInt = Convert.ToInt32 (str); //ERROR

[Jon Skeet [C# MVP]]

Denis Dougall wrote:

Using Regular expressions is the most cost effective way.

What exactly due you mean by "cost effective" here? It certainly isn't
the cheapest way of working - it's fairly easy to write a hard-coded
check which is many times quicker than a regular expression.

Using a regular expression is more efficient than using a try/catch,
but arguably harder to read/debug. (It depends on your level of regex
ability.)

Jon