Adventures in Programming

Case Sensitivity means a lower case c is considered a different character from an upper case C. In the hello world program this program will compile without errors and run.

#include<iostream.h>
int main()
  {
      cout <<"Hello World" << endl;
      return 0;
   }//end main

If cout was spelled with a capital C instead of a lower case c, a compile time error would result and the program will not run until it is corrected. This program with a capital C -

#include<iostream.h>
int main()
  {
      Cout <<"Hello World" << endl;
      return 0;
   }//end main

Will produce these errors -

Compiling...
kedigh-helloworld-adven07.cpp
C:\Program Files\Microsoft Visual Studio\MyProjects\kedigh_helloworld_adven07\kedigh-helloworld-adven07.cpp(5) : error C2065: 'Cout' : undeclared identifier
C:\Program Files\Microsoft Visual Studio\MyProjects\kedigh_helloworld_adven07\kedigh-helloworld-adven07.cpp(5) : error C2297: '<<' : illegal, right operand has type 'char [12]'
Error executing cl.exe.

kedigh-helloworld-adven07.obj - 2 error(s), 0 warning(s)

Remember to always look at the first error and correct it. The compiler doesn't know what Cout is.