Converting input strings to integers

[Dave]

Is there a standard .NET way to convert input strings to their closest integer
equivalent? In VB.NET I basically do a "CInt" and it takes care of most of
the problem (except for null values).

My first (pathetic non-working) attempt is the following - it currently fails
on non-numeric input or non-integer numbers. Am I totally out to lunch? Or
will I need to convert to a char array and look at each character, etc? I'm
willing to methodically go through that process, so I don't expect anyone
to write that code for me, but I have a hunch I'm going down the wrong track
on this. And of course I've named it "CInt" as any VB diehard would have
done

public static int CInt(object oValue)
{
if (oValue == null || System.Convert.IsDBNull(oValue))
{
//default null to 0:
return 0;
}

string sString = oValue.ToString().Trim();
if (sString == "")
{
//default empty string to 0:
return 0;
}

return int.Parse(sString, NumberStyles.Any);
}

[Russell Jones]

Look at the various integer types' Parse method. Or see the Convert.ToInt32
method (also see Convert to convert to other integer types). Or feel free to
import the VB namespace and use CInt (and other VB commands) directly.

"Dave" <dave_doknjas@yahoo.ca> wrote in message
news:3f319a37$1@tnews.web.devx.com...
>
> Is there a standard .NET way to convert input strings to their closest
integer
> equivalent? In VB.NET I basically do a "CInt" and it takes care of most of
> the problem (except for null values).
>
> My first (pathetic non-working) attempt is the following - it currently
fails
> on non-numeric input or non-integer numbers. Am I totally out to lunch? Or
> will I need to convert to a char array and look at each character, etc?
I'm
> willing to methodically go through that process, so I don't expect anyone
> to write that code for me, but I have a hunch I'm going down the wrong
track
> on this. And of course I've named it "CInt" as any VB diehard would have
> done
>
> public static int CInt(object oValue)
> {
> if (oValue == null || System.Convert.IsDBNull(oValue))
> {
> //default null to 0:
> return 0;
> }
>
> string sString = oValue.ToString().Trim();
> if (sString == "")
> {
> //default empty string to 0:
> return 0;
> }
>
> return int.Parse(sString, NumberStyles.Any);
> }
>

[Dave]

"Russell Jones" <arj1@northstate.net> wrote:
>Look at the various integer types' Parse method. Or see the Convert.ToInt32
>method (also see Convert to convert to other integer types). Or feel free
to
>import the VB namespace and use CInt (and other VB commands) directly.
>
>"Dave" <dave_doknjas@yahoo.ca> wrote in message
>news:3f319a37$1@tnews.web.devx.com...
>>
>> Is there a standard .NET way to convert input strings to their closest
>integer
>> equivalent? In VB.NET I basically do a "CInt" and it takes care of most
of
>> the problem (except for null values).
>>
>> My first (pathetic non-working) attempt is the following - it currently
>fails
>> on non-numeric input or non-integer numbers. Am I totally out to lunch?
Or
>> will I need to convert to a char array and look at each character, etc?
>I'm
>> willing to methodically go through that process, so I don't expect anyone
>> to write that code for me, but I have a hunch I'm going down the wrong
>track
>> on this. And of course I've named it "CInt" as any VB diehard would have
>> done
>>
>> public static int CInt(object oValue)
>> {
>> if (oValue == null || System.Convert.IsDBNull(oValue))
>> {
>> //default null to 0:
>> return 0;
>> }
>>
>> string sString = oValue.ToString().Trim();
>> if (sString == "")
>> {
>> //default empty string to 0:
>> return 0;
>> }
>>
>> return int.Parse(sString, NumberStyles.Any);
>> }
>>
>
I'm currently using the int type's Parse method from within my routine, but
the problem is (and also with the Convert namespace) is that I'll have to
resort to catching exceptions in this process and I'd rather not do that
as part of normal logic.

Import the VB namespace? *** GASP ***
Ok, maybe, if I have to.

[Len Weaver]

Hello Dave,

> Is there a standard .NET way to convert input strings to their closest
integer
> equivalent? In VB.NET I basically do a "CInt" and it takes care of
most of
> the problem (except for null values).

Try the static Double.TryParse method.

using System.Globalization;

bool success;
int intValue;
double doubleValue;
string x = "1234";

success = Double.TryParse( x, NumberStyles.Integer,
CultureInfo.CurrentCulture,
out doubleValue )

if( success ) intValue = (int)doubleValue;

If it can't perform the conversion it will return false, which is
better than throwing an exception.

Hope this helps,
Len

[Dave]

"Len Weaver" <len.weaver@meritsoft.net> wrote:
>Hello Dave,
>
>> Is there a standard .NET way to convert input strings to their closest
>integer
>> equivalent? In VB.NET I basically do a "CInt" and it takes care of
>most of
>> the problem (except for null values).
>
> Try the static Double.TryParse method.
>
>using System.Globalization;
>
>bool success;
>int intValue;
>double doubleValue;
>string x = "1234";
>
>success = Double.TryParse( x, NumberStyles.Integer,
> CultureInfo.CurrentCulture,
> out doubleValue )
>
>if( success ) intValue = (int)doubleValue;
>
> If it can't perform the conversion it will return false, which is
>better than throwing an exception.
>
>Hope this helps,
>Len
>
>
Perfect!! Thanks Len!
I couldn't find anything relevant for the int type, so I didn't even bother
to look at the double type. This is exactly the kind of thing I was looking
for.

[vatzcar]

thanx Len, i'm kinda n00b in VC# porting myself from VB6. This is exactly what i was looking 4.

[dkroger]

You could also use the IsNumeric method, but that would also require importing VB.

[edburdo]

Unfortunately the TryParse is only available for Double. I wish it was available for other conversions...

[pallavi]

Thanks Len
I was searching for the same.

Is the similar way available for converting String array to Double array ?

Actually I used

Dim values() As String = New String() {"3", "4", "5", "6"}
Dim returnValue() As Double = New Double() {}
returnValue = Array.ConvertAll(values, New Converter(Of String, Double)(AddressOf StringToDouble))

Public Shared Function StringToDouble(ByVal str As String) As Double
        Dim success As Boolean
        Dim doubleValue As Double
        success = Double.TryParse(Str, doubleValue)
        If success = True Then
            Return doubleValue
        Else
            Return 0
        End If
End Function

Do you know any other effective way ?

[Hack]

Is this way working for you or are you getting errors?

[pallavi]

Hack, its working properly.

[yhilewitz]

Try the following as a c# IsNumeric Function:

private bool IsNumeric(object oTst)
{
double nDbl = new double();
string strTst = Convert.ToString(oTst);
bool bNumeric = double.TryParse(strTst,
System.Globalization.NumberStyles.Any, null, out nDbl);
return bNumeric;
}