Week 2 lecture notes

• Functions
• Arrays
• Strings

Functions

• control flow
• how do you call them
• functions have types and values -- expressions
• void functions

Writing functions

• definition vs. declaration
• parameter lists
• scope rules (unlike Scheme!)

Examples

• factorial
• prime number tests

Procedural abstraction

• "black box"
• modularity
• Higher order functions?
• function pointers

Parameter passing

• value vs reference(important w/ assignment)
• references vs pointers
• can I pass functions?

Function templates

• meta-code
• untypes
• compiler issues

Arrays

• Scheme lists vs. arrays
  • typed vs. untyped
  • cost of access
  • closeness to machine
  • Dr.Scheme vectors vs. lists
• basic syntax
• memory layout

Dynamically memory management

• why do we care?
• stack and heap
• new and delete (explicit garbage collection! c.f. Scheme, Java)
• malloc, free (C legacy)
• getting a dynamic array

Some array algorithms

• passing arrays to functions
• returning arrays from functions
• sorting
• searching
• reduction
• cost of addition/deletion

Arrays of stuff

• What can go in?
• numbers
• function pointers?
• arrays
• characters

Characters

• single quote delimited
• letters, numbers, special characters (ASCII - Deitel appendix B)
• equivalent to integers (sort of)
• Escape characters '\n','\t', etc

Strings

• Arrays of characters (pointer to first character in string)
• Null-terminated ('\0')
• Literal: char color[] = "blue";
• In editing, make sure you keep room for the '\0'
• arrays of strings
• References: K&R, p. 249, Deitel Ch. 5
• some C library routines