1. 16.216 ECE Application Programming
Instructor: Dr. Michael Geiger
Fall 2013
Lecture 12
Exam 1 Preview

2. ECE Application Programming: Exam 1 Preview
Lecture outline
Announcements/reminders
Program 3 regrades due 10/4
Program 4 due 10/7
Exam 1: Wednesday, 10/2
Will be allowed one 8.5” x 11” double-sided note sheet
Final exam scheduled: Wed. 12/18, 8-11 AM
Today’s lecture: Exam 1 Preview
General exam notes
Review of material
6/2/2018
ECE Application Programming: Exam 1 Preview

3. ECE Application Programming: Exam 1 Preview
Exam 1 notes
Allowed one 8.5” x 11” double-sided sheet of notes
No other notes
No electronic devices (calculator, phone, etc.)
Exam will last 50 minutes
We’ll start at 12:00—please be on time!!
Covers all lectures through Friday
You will not be tested on design process, IDEs
Material starts with basic C program structure
3 questions
1 multiple choice
1 code reading
1 code writing (complete 2 of 3 parts; all 3 for extra credit)
6/2/2018
ECE Application Programming: Exam 1 Preview

4. Review: Basic C program structure
Preprocessor directives
#include: typically used to specify library files
#define: generally used to define macros
We’ll use to define constants
Main program
Starts with: int main() or void main()
Enclosed in block: specified by { }
Ends with return 0;
Indicates successful completion
Not used if main() is void
Basic output
Call printf(<string>);
<string> can be replaced by characters enclosed in double quotes
May include escape sequence, e.g. \n (new line)
6/2/2018
ECE Application Programming: Exam 1 Preview

5. Review: Data types, variables, constants
Four basic data types
int, float, double, char
Constants
Discussed viable ranges for all types
#define to give symbolic name to constant
Variables
Have name, type, value, memory location
Variable declarations: examples
int x;
float a, b;
double m = 2.35;
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ECE Application Programming: Exam 1 Preview

6. Review: printf() and scanf() basics
To print variables (or constants), insert %<type> in your printf() format string
%c: single character
%d or %i: signed decimal integer
%u: unsigned decimal integer
%x or %X: unsigned hexadecimal integer
%f: float
%lf: double
%s: string
Each %<type> must correspond to a variable or constant that follows
printf("a=%f, b=%f",a,b);
To read input, use same format specifiers in scanf() format string, followed by addresses of variables
scanf("%d %f",&hours,&rate);
6/2/2018
ECE Application Programming: Exam 1 Preview

7. ECE Application Programming: Exam 1 Preview
Review: field width
Format specifier for printf() takes form:
%[flags][width][.precision]
Field width: minimum # chars to be printed
Never truncates—if more chars than width, prints all
Default behavior—right justify value, print spaces
printf(“%10d”, n); 
(8 spaces, then number 12)
Flags allow you to add sign (+), left justify (-), and add leading zeroes (0)
printf(“%+-10d”, n);  +12_______
(Number 12 with sign, then 7 spaces)
printf(“%010d”, n); 
To use a variable to specify field width, use * as the width
printf(“%*d”, n, n); 
(Field width = 12  10 spaces, then the number 12)
6/2/2018
ECE Application Programming: Exam 1 Preview

8. ECE Application Programming: Exam 1 Preview
Review: precision
Format specifier for printf() takes form:
%[flags][width][.precision]
Specifying precision:
# chars after decimal point for FP (%f, %lf)
Rounds last digit
printf(“%.1lf”, x);  3.8
printf(“%.0lf”, x);  4
Minimum # chars for integer (%d, %i, %u, %x)
Does not truncate; will pad with leading 0s
printf(“%.3d”, n);  012
Max # chars for string (%s)
printf(“%.5s”, “one two”);  one t
No effect for char (%c)
As with field width, can use * to specify that field width is a variable
6/2/2018
ECE Application Programming: Exam 1 Preview

9. ECE Application Programming: Exam 1 Preview
Review: C operators
Operator
Associativity
Innermost ( )
Left to right
Unary -
Right to left
* / %
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ECE Application Programming: Exam 1 Preview

10. Review: Operators and statements
Operators can be used either with constants or variables
More complex statements are allowed
e.g. x = ;
Parentheses help you prioritize parts of statement
Makes difference with order of operations
x = * 3
is different than
x = (1 + 2) * 3
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ECE Application Programming: Exam 1 Preview

11. ECE Application Programming: Exam 1 Preview
Review: if statements
Conditional execution using if statements:
Form:
if (<expression>)
<statement>
[ else brackets show
<statement> ] else is optional
Expression frequently uses relational operators to test equality/inequality
< > <= >= == !=
e.g., if (x <= 5)
Can combine conditions using logical operators
AND : && OR: ||
e.g., if ((x <= 5) && (x > 0))
Can test if condition is false using logical NOT: !
e.g., if (!(x < 5))
6/2/2018
ECE Application Programming: Exam 1 Preview

12. Review: switch statements
When checking multiple exact values for expression, more sense to use switch statement
switch (<expr>) {
case <val1> :
...
break;
case <val2> :
default: }
break allows you to exit switch statement after completing code
Otherwise, program will continue to run through cases until finding break
default covers any values without specific case
6/2/2018
ECE Application Programming: Exam 1 Preview

13. Review: while/do-while loops
Used for repetition of code
while (<expression>)
<statement>  loop body
do { <statements> } while ( <expression> );
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ECE Application Programming: Exam 1 Preview

14. ECE Application Programming: Exam 1 Preview
Review: for loops
for (<init var>; <test>; <change var>)
<statements>
Operators to directly change variable
x++, x--  post-increment/decrement
++x, --x  pre-increment/decrement
+=, -=, *=, /=  augmented assignment
6/2/2018
ECE Application Programming: Exam 1 Preview

15. ECE Application Programming: Exam 1 Preview
Final notes
Next time
Exam 1
Reminders:
Program 3 regrades due 10/4
Program 4 due 10/7
Exam 1: Wednesday, 10/2
Will be allowed one 8.5” x 11” double-sided note sheet
6/2/2018
ECE Application Programming: Exam 1 Preview