Variables

Include Files
- Pull what is necessary from included library’s and inserts into Binary

Standard Libraries
- Math and Standard Operations

The Preprocessor (More on this in CSE 230)
- Strips our Comments
- Makes substitutions for named constants
- insert definition of included function files (Reserves space for them)

Every C Program must have a main function
int main (void)

• Execution begins and ends with the main function
• Program Statements are executed sequentially
• Execution begins at first statement of main
• ( ) are used to specific function parameters
• { } enclose the body, are used to group statements
• If you do not declare int main you do not need to end with return 0;
• \n means “go to the next line”
• \ backslash key is an escape character
• \t means tab
• return 0; – Signals successful end of your program to the operating system
• Many functions return values, ie: Mathematical functions

Program Structure

1. Preprocessor directives
   1. #include-d files
   2. Other definitions/Declarations
2. Supporting functions
3. Main functions

Variables are named blocks of memory
Intergers
Regular int = 4 bytes
Short int = 2 bytes

Floating Points
Float = 4 bytes (standard accuracy, 8 digits after decimal)
Double = 8 bytes (better accuracy, more decimals)

Char – 1 byte

Every memory block has a # and your var is assigned a # (by Preprocessor?)