CS120 - Day 7 - Structs
==================================

Update game.c example by 
	- creating a Player struct
	- making an array of players
	- fix gameplay

Structures
    - way of creating a data type with multiple data parts
	- two components:
		- define struct
		- declare variables

	struct sname {
		fields (variable declarations)
	}  [var declarations] ;

	- referencing
		- dot operator for struct field vars
		- arrow operator for struct * vars
		- equivalence: sptr->part == (*sptr).part
			highest precedence: () [] . ->

	- initialize in declaration
		- use {} and list of values for each part
		- if fewer values than parts, remainder init to 0 or NULL

	- passed by VALUE to functions by default!
	- can pass whole structure, or just an element of structure
	- good reason to pass with pointer but const protect

	struct SSNum {
		   int n1, n2, n3;
    } ssn;
	scanf("%d-%d-%d", &ssn.n1, &ssn.n2, &ssn.n3);
	printf("%03d-%02d-%04d\n", ssn.n1, ssn.n2, ssn.n3);

- typedef: must put typename at end of declaration
	typedef struct {
		fields;
	} typename;

	typename mything;


See code files: structsFail.c, structs.c, structs2.c


TOOL: indent 
- use it to automatically format your code consistently
    > indent mycode.c   reformat and overwrite your file, creates back-up?
    > indent mycode.c -o mycodePretty.c

- there are lots of customization options, look in the man pages
- personal favorites:
    -kr for kernigan & ritchie style
    -i4 for level indents of 4 spaces


The Problem:

Create a simplified database application for course listings.  Each
course in the database will have a unique two part number in
accordance with the JHU system: ddd.nnn where ddd is the department
number ranging from 001 to 700 and nnn is the course number ranging
from 100 to 899, inclusive.  Each course will also have a set of area
designators (any combination of HSNEQW, including none at all), a
number of credits which is a multiple of .5 between 0.5 and 4.5
inclusive, and a title which is at most 30 characters.

Operations:
- add a new course to the database such as:
  600.107 [E] Intro to Programming in Java (3.0)
- display an existing course based on course number (ddd.nnn format)
- display all the courses
- change a course name, based on course number (ddd.nnn)
- delete a course, specified by course number (ddd.nnn)
- display all courses with particular area designators (one or more)