CString

[kakan]

CString m_Str; m_Str="123ABC"; Index=atoi(m_Str);//return value is 123 Gives 123 too, and m_Str doesn't contain only numbers...

Alcohol. The cause of, and the solution to, all of life's problems - Homer Simpson

[Jorgen Sigvardsson]

Here's a small function I use for validating user input:

bool IsNumeric(const CString& str)
{
if(str.IsEmpty())
return false;

for(int i = 0; i < str.GetLength(); i++)
	if(str\[i\] < '0' || str\[i\] > '9')
		return false;

return true;

}

It only takes decimal non-negative integers into account. It's easy to extend for other types of numbers, should you want to.

-- Mit viel Oktan und frei von Blei, eine Kraftstoff wie Benziiiiiiin!

[_AnsHUMAN_]

speedy4711 wrote:

test if a CString contains only numbers?

here's one more solution. You can give this a try...

CString s="253453";
CComVariant v;
v=s;
if(v.ChangeType(VT_INT)==S_OK)
{
	CString str;str.Format ("%d",v.intVal );
	AfxMessageBox (str);
}

Somethings seem HARD to do, until we know how to do them. ;-)_AnShUmAn_

[KarstenK]

I looked over the responses, and I want to point to two possible problems. The first may be a leading Zero ( "0123" ) and the other is a value with a comma or a sign ( "-1,5" or "+ 2.7" ) I would resolve this with checking every char of being a digit or allowed other char.

Greetings from Germany

[SilentSilent]

_AnShUmAn_ wrote:

if(str.GetLength ()==str1.GetLength ())

Doesn't work with eg. CString str="0x1142654";

[SilentSilent]

Jörgen Sigvardsson wrote:

for(int i = 0; i < str.GetLength(); i++) if(str[i] < '0' || str[i] > '9') return false;

Doesn't work with eg. CString str="0x1142654";

[Jorgen Sigvardsson]

How often do you accept hexadecimal user input? And how hard would it be to extend it? I never claimed it would recognize all possible numeric syntaxes...

-- Mit viel Oktan und frei von Blei, eine Kraftstoff wie Benziiiiiiin!

[_AnsHUMAN_]

SilentSilent wrote:

Doesn't work with eg.

Since this value you are entering is a string x is treated as a character only, it doesn't represent a hexadecimal number nor did I check for this.So I would try and provide a solution for this... Thanks for pointing this out...

Somethings seem HARD to do, until we know how to do them. ;-)_AnShUmAn_

[David Crow]

Why don't you just use strtol()?

---

"Talent without discipline is like an octopus on roller skates. There's plenty of movement, but you never know if it's going to be forward, backwards, or sideways." - H. Jackson Brown, Jr.

"Judge not by the eye but by the heart." - Native American Proverb

[Zac Howland]

Here is a base-10 checker that allows for ,'s and -'s (but doesn't check for placement). You can easily extend it to check for proper placement of special characters (,'s, and -'s) as well as other base numbers and floating point numbers.

// function to check for base-10 digits only
bool is_digit_base10(const CString& str)
{
	static CString allowedChars = _T("0123456789,-");
	const unsigned int length = str.GetLength();
	for (unsigned int i = 0; i < length; ++i)
	{
		char buffer[2] = {0};
		buffer[0] = str[i];
		if (-1 == allowedChars.FindOneOf(buffer))
		{
			return false;
		}
	}
	return true;
}

If you decide to become a software engineer, you are signing up to have a 1/2" piece of silicon tell you exactly how stupid you really are for 8 hours a day, 5 days a week Zac