From 882ae24f13b65c8401d7ef943914ba2c29dde99a Mon Sep 17 00:00:00 2001
From: loshprung <lshprung@scu.edu>
Date: Wed, 15 Jan 2020 17:34:38 -0800
Subject: Added additional info about structures to 01-15.md

---
 01-15.md | 53 ++++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 44 insertions(+), 9 deletions(-)

(limited to '01-15.md')

diff --git a/01-15.md b/01-15.md
index bf362d1..a23c3b5 100644
--- a/01-15.md
+++ b/01-15.md
@@ -32,7 +32,7 @@ The code outputs the following:
 
 # Introduction to Structures in C
 
--`Earlier we talked about data types: int, char
+- Earlier we talked about data types: int, char
 - A Structure allows for multiple data types in one array
 - Structure Basics
 	- A structure is a collection of values, called members
@@ -47,6 +47,8 @@ struct name{
 };
 ```
 
+- The keyword struct signifies that this is a structure definition
+
 - Example:
 
 ```
@@ -58,17 +60,49 @@ struct info{
 };
 ```
 
-- Let's see the memory:
+- As can be seen in the example, multiple different data types are included as members of `info`
+- This example **does not allocate any memory**
+	- Instead, it simply tells C that now there is a new kind of data type called `struct info`
+
+- Let's create a sample `struct info`:
+
+```
+struct info real_info;
+struct info *p;
+```
+
+- Memory **is** allocated for real\_info
+- Member variables of a struct can be accessed using `.`
+	- For example:
 
-|   |   |
-| - | - |
-|   |   |
-| Real_Info  | 55 bytes of storage |
-|   |   |
+```
+p = &real_info //*p will point to real_info now
+real_info.number = 2;
+real_info.character = 'A';
+```
+
+- Let's see a visual representation of real\_info in memory
+
+| real_info.number | real_info.character | real_info.string[] | real_info.array[] |
+| - | - | - | - |
+| 2 | 'A' | ... | ... |
+
+- `real_info.string[]` and `real_info.array[]` show `...` because to show the full visual representation in memory, I would have to show `real_info.string[0]`, `real_info.string[1]`, etc.
+
+- To access structure members with a pointer (such as `*p` defined above), use `->`
+	- For example:
+
+```
+p->number = 2;
+0->character = 'B';
+p->array[0] = 3;
+```
 
-- You can also create pointers to data structures
+- The above code changes three members of real\_info in memory to the following:
 
-- Defines a structure type
+| real_info.number | real_info.character | real_info.string[] | real_info.array[0] |
+| - | - | - | - |
+| 2 | 'B' | ... | 3 |
 
 ---
 
@@ -81,3 +115,4 @@ struct node{
 };
 ```
 
+- We will talk more about links later
-- 
cgit