20. Variable Name Examples

• 
  void main() 
  { 
      const char LF = '\n';
      bool   FLAG_BUSY;
      int    social_security_number;
      double form1040a_field_33;
      bool   FLAG_BUSY = false;  // Error: variable already declared
      bool   flag_busy = false;  // OK, but extremely bad style
      double 1040a_total;        // Syntax error: first character must
                                 // be a letter or underscore 
  }