CS 111 - 1/24/17

Quiz 1

Q. 1 - Simple variable assignment, access and operation

Q. 2 - Highlighting Sequential Access

           x = 5
           y = x + 2
           x = 32
           print y     # the value of 7 is printed

Q. 3 - Order of Operation Precedence

         z = w + x * y

Assignment Statements are NOT the same as 
    Algebraic Statements

   For Example:

          x = x + 1

    The above is an invalid Algebraic Statement

    The above is an extremely Assignment Statement


      In assignment statements, 
        the right-hand-side of the statement is
           evaluated first
        then the resulting value is stored in the
           variable specified on the left-hand-side.

We have mentioned function, which are a collection
     of statements

Next: Turtle Drawings

     Take the programming ideas from Chapter 3

     Use the Application Domain Area from Chapter 17

     The best help/documentation for the Turtle Drawings
       is found in the help menu of the JES software

     Other documentation is found in Chapter 17 and
        the inside back cover of the text book.
        These two documents sources refer to 
          "Methods" rather than "Functions"

        The difference between "Methods and Functions"
          is largely organizational and syntactical

        Methods are a key element of Object Oriented 
           programming.


  Key Concept of Turtle Drawing
    1.   We have Turtle that live on a World

    2.   Each Turtle has a pen attached to its back.

    3.   As the turtle moves around the world (and if
           the pen is "down"), the turtle leave a line
           showing how it moved.
   
  Our job is the have the Turtles draw something specific

    The primary operations that we can tell a turtle to
      do is:
        - move forward
        - turn to change directions
        - lift the pen UP or place the pen DOWN
        - change colors for the pen (this is METHODS only)

Programming Goals with Turtle drawings
  - better understand sequential execution
  - understand the idea of iteration (i.e. Looping/repeating)
  - understand how to write our own functions