public bool isNumeric(string str) {
Regex pattern = new Regex("[^0-9]");
return !pattern.IsMatch(str);
}


Alfa values:


private bool IsAlpha(string str) {
Regex pattern = new Regex("[^a-zA-Z]");
return !pattern.IsMatch(str);
}


Alfa numeric values:

private bool isAlfaNumeric(string str) {
Regex pattern = new Regex("[^a-zA-Z0-9]");
return !pattern.IsMatch(str);
}


1. Good one

int main()

cout<<"Press Enter to continue...";
cin.get();
}


Well, this one really is “Press Enter to continue…”, which shouldn’t be a problem

2. Bad one

int main()
{

system.("PAUSE");
}

This one is very bad! If you want to know why, read this article:

http://www.gidnetwork.com/b-61.html

int main()
{
// do something
delay(5);
// delays 5 seconds
}



#include <sstream>

string toString(int n)
{
string str;
stringstream out;
out<
return str = out.str();
}