bool isEqual(int x, int y)
{
  return x == y;
}
int main()
{
  bool b = true;
  b = isEqual(3, 4);
  b = false;
  return 0;
}

bool cond = divisor > 0 && numerator / divisor > 0.1;

bool notADigit = c < '0' || c > '9';

bool isAChild = age < 18;
bool isAdult = !isAChild;

int main()
{
  int a = 1;
  int b = 2;
  if ( a < b )
    cout << "a < b\n";
  else if ( a > b )
    cout << "a > b\n";
  else
    cout << "a == b\n";
  if ( a > 0 )
    cout << "a is positive\n"0;
}

int maxOfThree( int a, int b, int c )
{
  if ( a < b )
    if ( b < c )
      return c;
    else
      return b;
  else if ( a < c )
    return c;
  else
    return a;
}

if ( e ); // extra semicoln means empty statements
  cout << "Hello"; // prints "Hello" even if e is false

if ( e )
  ; // nothing
else
  cout << "Hello";

int a = 0;
if ( a = 0 ) 
  cout << "Hello"; // never happens! Why?

if ( a < b )
  return true;
else
  return false;

return a < b;

int main()
{
  int i = getIntegerFromUser();
  cout << "Some stuff here\n";
  switch ( i )
  {
    case 1:
    case 3:
    case 5:
    case 7:
    case 9:
      cout << i << " is odd\n";
      break;
    case 0:
    case 2:
    case 4:
    case 6:
    case 8:
      cout << i << " is even\n";
      break;
    default:
      cout << i << " isn't in range 0 to 9\n";
      break;
  }
  cout << "Some more stuff here\n";
}

bool isDigit( char c )
{
  switch ( c )
  {
    case '0':
    case '1':
    case '2':
    case '3':
    case '4':
    case '5':
    case '6':
    case '7':
    case '8':
    case '9':
      return true;
    default:
      return false;
  }
}

int main()
{
  int score = getScoreFromUser();
  char grade = computeStudentsGrade( score );
  switch ( grade )
  {
    case 'A':
      cout << "Excellent!\n";
    case 'B':
      cout << "Good.\n";
    case 'C':
      cout << "Fair - just passed.\n";
    case 'D':
      cout << "Poor - See you next quarter.\n";
    case 'F':
      cout << "Failed - off to OCC.\n";
    defaut:
      cout "Invalid Grade " << grade << endl;
  }
}

bool isDigit(char c)
{
  switch ( c )
  {
    case '0'-'9': // will subtract '9' from '0'
      return true;
    default:
      return false;
  }
}

bool isDigit(char c)
{
  switch ( c )
  {
    case '0':
    case '1':
    case '2':
      /// do something here
    default:
      return false;
  }
}