Re: How to read a part of an integer

From:

"Jim Langston" <tazmaster@rocketmail.com>

Newsgroups:

comp.lang.c++

Date:

Wed, 9 May 2007 00:43:11 -0700

Message-ID:

<AYe0i.1178$gn1.76@newsfe04.lga>

"panther" <tharaka190@gmail.com> wrote in message
news:1178656110.931597.178690@p77g2000hsh.googlegroups.com...

Hi,
now i have a new problem.
Here is my codes.

using namespace std;

int main()
{

string number,number1,number2,number3;

cout << "Please enter your National ID Number :";
cin >> number;

while (number != "" ){

if (number.length() != 9)
{
cout <<"Input must be 9 digits. Try again.\n ";
break;
}

// if (! isdigit(number) )
// {
// cout <<" Only numbers 0-9 are allowed. Try again\n";
// break;
// }

else
{

number1 = number.substr(0,2);
number2 = number.substr(2,3);
number3 = number.substr(5,4);

int i = atoi(number1.c_str());
int j = atoi(number2.c_str());
int k = atoi(number3.c_str());
cout <<i<<endl;
cout <<j<<endl;
cout <<k<<endl;
break;
}
}

return 0;

}

The problem is isdigit() not work with the string. It for the
character. So how do i check the contain of the string?
Please help me.

Untested psuedo code again.

bool IsStringDigits( const std::string& Input ) // If isdigit doesn't
accept const char, remove const.
{
   for ( size_t i = 0; i < Input.length(); ++i )
      if ( ! isdigit( Input[i] ) )
         return false;
   return true;
}