// Learning Processing
  // Daniel Shiffman
  // http://www.learningprocessing.com
  
  // Example 4-1: Variable declaration and initialization examples
  int count = 0;          // Declare an int named count, assigned the value 0
  char letter = 'a';      // Declare a char named letter, assigned the value 'a'
  double d = 132.32;      // Declare a double named d, assigned the value 132.32
  boolean happy = false;  // Declare a boolean named happy, assigned the value false
  float x = 4.0;          // Declare a float named x, assigned the value 4.0
  float y;                // Declare a float named y (no assignment)
  y = x + 5.2;            // Assign the value of x plus 5.2 to the previously declared y
  float z = x*y + 15.0;   // Declare a variable named z, assign it the value which 
                             // is x times y plus 15.0.