ECE160 - Lesson 5

Pointers and Arrays

Professor Hong

## Review & Questions

## The C Preprocessor

## File Inclusion * <code>#include "filename.h"</code> - includes file in directory of where the source program was found; else follows an implementation defined rule. * <code>#include <filename.h></code> - follows an implementation-defined rule to find the file * We specify the directories inside the makefile with the -I. flag

## Macro Substitution * <code>#define name replacement text</code> - can also be used to substitute macros * Be careful as it literally just replaces a name with the replacement text. * Be careful with your order of operations.

## Conditional Inclusions ``` #if !defined(HDR) #define HDR /* contents of hdr.h go here */ #endif ``` * Useful for not including code you've already included when compiling.