1. EECE.2160 ECE Application Programming
Instructors:
Dr. Michael Geiger & Dr. Lin Li
Spring 2019
Lecture 2:
Basic C program structure
IDE demos

2. ECE Application Programming: Lecture 2
Lecture outline
Announcements/reminders
Chapter 1 exercises due Monday, 1/28
Textbook exercises always due 3 days after related lecture—check ”Assignments” tab regularly!!!
Program 1 due Wednesday, 1/30
10 points: register for access to the course textbook
10 points: introduce yourself to your instructor
30 points: complete simple C program
Today’s lecture
Basic C program structure
Comments
IDE demo
4/23/2019
ECE Application Programming: Lecture 2

3. Review: Basic C program structure
#include <stdio.h> int main() { printf("Hello World!\n"); return 0; }
Preprocessor directives
#include: typically used to specify library files
<stdio.h> is built-in standard input/output library
Main function
Starts with: int main() or void main()
Enclosed in block: specified by { }
Ends with return 0;
Indicates successful completion
4/23/2019
ECE Application Programming: Lecture 2

4. Review: Basic C program structure
#include <stdio.h> int main() { printf("Hello World!\n"); return 0; }
Basic output
Call printf(<string>);
<string> can be replaced by characters enclosed in double quotes
May include escape sequence, e.g. \n (new line)
4/23/2019
ECE Application Programming: Lecture 2

5. Variation #1 of first program
What does this program print?
#include <stdio.h> int main() { printf("Hello"); printf("there"); printf("World!"); return 0; }
Output: HellothereWorld!
No newlines  all one line of output
No spaces  words printed next to one another
4/23/2019
ECE Application Programming: Lecture 2

6. Variation #2 of first program
What does this program print?
#include <stdio.h> int main() { printf("Hello\n"); printf("there\n"); printf("World!\n"); return 0; }
Output: Hello
there
World!
Each newline moves cursor to next line
4/23/2019
ECE Application Programming: Lecture 2

7. Variation #3 of first program
What does this program print?
#include <stdio.h> int main() { printf("Hello\nthere\nWorld!\n"); return 0; }
Output: Hello
there
World!
Works the same as variation #2
One printf() call can produce multiple output lines
Proper style: one printf() call per output line unless lines are short
4/23/2019
ECE Application Programming: Lecture 2

8. Variation #4 of first program
#include <stdio.h> int main(){printf ("Hello\nthere\nWorld!\n");return 0;}
Compiler doesn’t care about white space
#include must be on its own line
Compiler figures out start/end of blocks, statements using specific symbols
Curly braces { } for block
Semicolon ; for end of statement
Works the same as variations #2 & #3 …
… but looks much worse
4/23/2019
ECE Application Programming: Lecture 2

9. ECE Application Programming: Lecture 2
Code readability
Readability wouldn’t matter if:
Entire code project written by one person
All code was in same file
Same person is the only one to use the code
Code was used only for a short period of time
More typically:
Projects are split—multiple programmers and files
Code usually reused
Multiple users
Used/adapted (hopefully) over long period of time
You may reuse code ... but forget what you originally wrote!
Bottom line: code needs to be readable
4/23/2019
ECE Application Programming: Lecture 2

10. ECE Application Programming: Lecture 2
Comments
C allows you to add comments to your code
Single line comments: start with //
Multi-line comments: start with /*
end with */
Typical uses
Multi-line comment at start of program with
Author’s name (& other info if appropriate)
Date started/modified
Description of overall file functionality
For individual code sections
Comment for major section of code performing single function
Comment for single line of code if that line alone is important
Comments should be informative
Takes some time to learn what should be commented
4/23/2019
ECE Application Programming: Lecture 2

11. ECE Application Programming: Lecture 2
Comment example
/* EECE.2160: ECE Application Programming 4/23/2019 hello.c: Intro program to demonstrate basic C program structure and output */ #include <stdio.h> // Main program: prints basic string and exits int main() { printf("Hello World!\n"); // Comment return 0; }
4/23/2019
ECE Application Programming: Lecture 2

12. ECE Application Programming: Lecture 2
Assignment #1
Basic assignment to ensure you can write, run, and submit programs
Write a short program that prints (each item on its own line):
The name of the class
The current semester
The days on which lectures meet
The instructors’ names
For this assignment, spacing matters!!!
4/23/2019
ECE Application Programming: Lecture 2

13. ECE Application Programming: Lecture 2
IDE demos
zyBooks IDE demo (Section 1.11 of the text)
Basics of writing and compiling code
Develop mode vs. submit mode
Dealing with errors
Compiler errors
Incorrect output
Test cases
Visual Studio demo
Setting up a project
Building and running a project
Getting project to pause at the end
4/23/2019
ECE Application Programming: Lecture 2

14. ECE Application Programming: Lecture 2
Final notes
Next time
Data types
Variables
Reminders
Chapter 1 exercises due Monday, 1/28
Textbook exercises always due 3 days after related lecture—check ”Assignments” tab regularly!!!
Program 1 due Wednesday, 1/30
10 points: register for access to the course textbook
10 points: introduce yourself to your instructor
30 points: complete simple C program
4/23/2019
ECE Application Programming: Lecture 2