IsNumeric: Convert.ToInt32 vs. Convert.ToInt64

[sck10]

Hello,

I am trying to test for IsNumeric using C# with the following:

public bool IsNumeric(object TestValue)
{
try
{
int i = Convert.ToInt32(TestValue.ToString());
return true;
}
catch (FormatException)
{
return false;
}
}
If I use ToInt32, I get the error: "System.OverflowException: Value was
either too large or too small for an Int32." For a value of 9999999999

If I try: int i = Convert.ToInt64(TestValue.ToString());

Cannot implicitly convert type 'long' to 'int'. An explicit conversion
exists (are you missing a cast?)

Any assistance on why Convert.ToInt64 is failing would be appreciated.
Thanks, sck10

[Mark Rae]

"sck10" <sc***@online.nospamwrote in message
news:Oy****************@TK2MSFTNGP02.phx.gbl...

If I try: int i = Convert.ToInt64(TestValue.ToString());

Cannot implicitly convert type 'long' to 'int'. An explicit conversion
exists (are you missing a cast?)

Any assistance on why Convert.ToInt64 is failing would be appreciated.

Er, because you're trying to plug an Int64 into an Int32... :-)

Would this work...?
byte i = Convert.ToInt64(TestValue.ToString());

Why not...?

For the same reason, neither will:
int i = Convert.ToInt64(TestValue.ToString());

This will, though...
Int64 i = Convert.ToInt64(TestValue.ToString());

[David Anton]

Why are you still trying the exception catching approach? This question was
answered the last time you posted a few hours previously.
--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
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"sck10" wrote:

Hello,

I am trying to test for IsNumeric using C# with the following:

public bool IsNumeric(object TestValue)
{
try
{
int i = Convert.ToInt32(TestValue.ToString());
return true;
}
catch (FormatException)
{
return false;
}
}
If I use ToInt32, I get the error: "System.OverflowException: Value was
either too large or too small for an Int32." For a value of 9999999999

If I try: int i = Convert.ToInt64(TestValue.ToString());

Cannot implicitly convert type 'long' to 'int'. An explicit conversion
exists (are you missing a cast?)

Any assistance on why Convert.ToInt64 is failing would be appreciated.
Thanks, sck10

[sck10]

Thanks David,

I am using the approach you presented earlier (from your website), but I was
interested in learning why .ToInt64 was not working.

Thanks again...
"David Anton" <Da********@discussions.microsoft.comwrote in message
news:E9**********************************@microsof t.com...

Why are you still trying the exception catching approach? This question
was
answered the last time you posted a few hours previously.
--
David Anton
www.tangiblesoftwaresolutions.com
Instant C#: VB to C# converter
Instant VB: C# to VB converter
Instant C++: C#/VB to C++ converter
C# Code Metrics: Quick metrics for C#
"sck10" wrote:

>Hello,

I am trying to test for IsNumeric using C# with the following:

public bool IsNumeric(object TestValue)
{
try
{
int i = Convert.ToInt32(TestValue.ToString());
return true;
}
catch (FormatException)
{
return false;
}
}
If I use ToInt32, I get the error: "System.OverflowException: Value was
either too large or too small for an Int32." For a value of 9999999999

If I try: int i = Convert.ToInt64(TestValue.ToString());

Cannot implicitly convert type 'long' to 'int'. An explicit conversion
exists (are you missing a cast?)

Any assistance on why Convert.ToInt64 is failing would be appreciated.
Thanks, sck10

[daniel]

I recommend to use a regular expression to IsNumeric Method, is more
eficcient.

regards
daniel

"sck10" <sc***@online.nospamwrote in message
news:Oy****************@TK2MSFTNGP02.phx.gbl...

Hello,

I am trying to test for IsNumeric using C# with the following:

public bool IsNumeric(object TestValue)
{
try
{
int i = Convert.ToInt32(TestValue.ToString());
return true;
}
catch (FormatException)
{
return false;
}
}
If I use ToInt32, I get the error: "System.OverflowException: Value was
either too large or too small for an Int32." For a value of 9999999999

If I try: int i = Convert.ToInt64(TestValue.ToString());

Cannot implicitly convert type 'long' to 'int'. An explicit conversion
exists (are you missing a cast?)

Any assistance on why Convert.ToInt64 is failing would be appreciated.
Thanks, sck10