Re: Is this code to find an int in a string okay ?

In article
<85ec7280-977f-4651-a3f4-2199b4150d10@j44g2000hsj.googlegroups.com>,
 Diwa <shettydiwakar@gmail.com> wrote:


What you have is fine, just wrap it into a function and it will look
like this:

string get_int( const string& s )
{
   string result;
   string::size_type front = s.find_first_of( "0123456789" );
   if ( front != string::npos )
   {
      string::size_type back =
            s.find_first_not_of( "0123456789", front );
      result.assign( s, front, back - front );
   }
   return result;
}

.... or you can get creative:

bool is_digit( char c )
{
   return isdigit( c );
}

string get_int( const string& s )
{
   string::const_iterator front = find_if( s.begin(), s.end(),
         &is_digit );
   string::const_iterator back = find_if( front, s.end(),
         compose1( logical_not<bool>(), ptr_fun( &is_digit ) ) );
   return string( front, back );
}

(note: compose1 is part of STL, not part of the standard.)

Once you have the above function, you can operate on your array with
transform.

int main()
{
   vector<string> strs ;
   strs.push_back("KFStat30A");
   strs.push_back("KFStat2A");
   strs.push_back("555555");
   strs.push_back("KKKKKK");
   strs.push_back("KKKK555");

   vector<string> ints;
   
   transform( strs.begin(), strs.end(),
         back_inserter( ints ), &get_int );
   
   for ( int i = 0; i < strs.size(); ++i )
      cout << strs[i] << ' ' << ints[i] << '\n';
}