1. EECE.2160 ECE Application Programming
Instructor:
Dr. Michael Geiger
Fall 2018
Lecture 37:
Exam 3 Preview

2. ECE Application Programming: Exam 3 Preview
Lecture outline
Announcements/reminders
No Thursday office hours this week
Th 12/13: last day of classes; Program 8 due
M 12/17: Exam 3, 3-6 PM, Ball 210
Course evals online; will also have hard copies available
You’ll submit eval at exam
W 12/19: All code due by 12:00 PM (noon)
Program 9: Worth up to 4 points extra credit on final avg
Resubmission deadline for P7 & P8
Today’s class: exam 3 preview
Exam outline
Review of material
5/25/2019
ECE Application Programming: Exam 3 Preview

3. ECE Application Programming: Exam 3 Preview
Exam 3 notes
Allowed one 8.5” x 11” two-sided note sheet
No other notes or electronic devices
Exam lasts 3 hours (but written for ~50 min)
Coverage
All lectures after Exam 2 (lectures 26, 29-36)
Format similar to Exams 1 & 2
Code reading, writing, multiple choice questions
One 10 point extra credit question at end
For this exam, you may attempt the extra credit question even if you haven’t attempted to solve all other problems
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ECE Application Programming: Exam 3 Preview

4. ECE Application Programming: Exam 3 Preview
Exam 3 outline (CR = code reading, CW = code writing, MC = multiple choice)
Structures: CR/CW questions on
Basic structure accesses
Dot operator (i.e., s1.x)
Pointer access (i.e., p->GPA)
Arrays of structures
Nested structures
File input/output: MC/CW questions on
fopen()/fclose()
Text file I/O using fprintf()/fscanf()
Binary file I/O using fread()/fwrite()
Standard I/O streams: stdin, stdout
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ECE Application Programming: Exam 3 Preview

5. ECE Application Programming: Exam 3 Preview
Exam 3 outline (CR = code reading, CW = code writing, MC = multiple choice)
Character/line I/O: CR/MC questions on
fgetc(), getchar(), ungetc()
fgets()
Bitwise operators: CR/MC questions on
Operator basics
Hexadecimal output
Extra credit: may focus on any topic above
Should clearly understand earlier material, too
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ECE Application Programming: Exam 3 Preview

6. ECE Application Programming: Exam 3 Preview
Review: Structures
User-defined types; example:
typedef struct {
char first[50];
char middle;
char last[50];
unsigned int ID;
double GPA;
} StudentInfo;
Can define variables of that type
Scalar: StudentInfo student1;
Array: StudentInfo classList[10];
Pointer: StudentInfo *sPtr;
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ECE Application Programming: Exam 3 Preview

7. Review: structures (continued)
Initialization very similar to array initialization:
StudentInfo student1 =
{ “John”, ‘Q’, “Smith”,
, 3.75 };
Access members using
Dot operator: student1.middle = ‘J’;
Arrow (if pointers): sPtr->GPA = 3.5;
Typically passed to functions by address
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ECE Application Programming: Exam 3 Preview

8. Review: Nested structures
Structures can contain other structures:
typedef struct {
char first[50]; // First name
char middle; // Middle initial
char last[50]; // Last name
} Name;
Name sname; // Student name
unsigned int ID; // ID #
double GPA; // Grade point
} SINew;
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ECE Application Programming: Exam 3 Preview

9. Review: Nested structure accesses
Will need multiple dot operators to access field within nested structure
Given SINew s1;
s1.sname  Name structure within s1
s1.sname.middle  middle initial of name within s1
Structure pointer typically only to top-level structure
Given SINew *sp = &s1;
sp->sname  Name structure within s1
sp->sname.middle  middle initial of name within s1
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ECE Application Programming: Exam 3 Preview

10. ECE Application Programming: Exam 3 Preview
Review: File I/O
Open file: FILE *fopen(filename, file_access)
Close file: fclose(file_handle)
Formatted I/O:
fprintf(file_handle, format_specifier, 0+ variables)
fscanf(file_handle, format_specifier, 0+ variables)
Unformatted I/O:
size_t fwrite(pointer, element size, # elements, file_handle)
size_t fread(pointer, element size, # elements, file_handle)
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ECE Application Programming: Exam 3 Preview

11. ECE Application Programming: Exam 3 Preview
Review: Generic I/O
Special I/O streams in C
stdin: standard input
stdout: standard output
printf(“Hello\n”) ==
fprintf(stdout, “Hello\n”);
scanf(“%d”, &x) ==
fscanf(stdin, “%d”, &x);
Can write generic code that deals either with specific file or standard input/output
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ECE Application Programming: Exam 3 Preview

12. ECE Application Programming: Exam 3 Preview
Review: End of file
Two ways to check for end of file:
Text files: Check if fscanf() == EOF
More common: do fscanf() as part of loop condition, and continue while EOF not reached
e.g. while (fscanf(fp, “%d”, &y) != EOF)
Binary files: feof(file_handle);
Note: both functions indicate EOF after failed read operation
Must try to read data and discover that there’s nothing to read before testing for EOF
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ECE Application Programming: Exam 3 Preview

13. Review: character/line input
Character input
int fgetc(FILE *stream);
int getchar();
int ungetc(int c, FILE *stream);
Line input
char *fgets(char *s, int n, FILE *stream);
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ECE Application Programming: Exam 3 Preview

14. Review: binary and hexadecimal
All data encoded in binary (base 2)
Useful knowing bit patterns to evaluate bitwise ops
Hexadecimal (base 16) used with bitwise ops
Closer to binary than base 10 is
Each hexadecimal digit = 4 bits
Leading 0x indicates hexadecimal constant
Digits 0-9 same as decimal, = A-F
0x0 = 00002, 0x1 = … 0x9 = 10012
0xA = 10102, 0xB = … 0xF = 11112
Variables typically declared as unsigned int
Strictly non-negative whole numbers
32 bits in length
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ECE Application Programming: Exam 3 Preview

15. Review: bit manipulation
Bitwise operators: | & ^ ~
Used for desired logical operations
Used to set/clear bits
Bit shifts: << >>
Used to shift bits into position
Used for multiplication/division by powers of 2
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ECE Application Programming: Exam 3 Preview

16. Review: hexadecimal output
To print a number in hex, use %x or %X
%x prints characters a-f in lowercase
%X prints characters A-F in uppercase
To show leading 0x, use the # flag
To show leading 0s, use precision with total # chars
Field width + 0 flag also works unless value = 0
Examples (assume var1 = 0x1A2B)
printf(“%x”, var1)  1a2b
printf(“%X”, var1)  1A2B
printf(“%#x”, var1)  0x1a2b
printf(“%.6x”, var1)  001a2b
printf(“%#.6x”, var1)  0x001a2b
5/25/2019
ECE Application Programming: Exam 3 Preview

17. ECE Application Programming: Exam 3 Preview
Next time
Exam 3: Monday, 12/17, 3-6 PM, Ball 210
Don’t forget to complete your course eval before exam!
Hard copies available from my office
Reminders:
No Thursday office hours this week
Th 12/13: last day of classes; Program 8 due
W 12/19: All code due by 12:00 PM (noon)
Program 9: Worth up to 4 points extra credit on final avg
Resubmission deadline for P7 & P8
5/25/2019
ECE Application Programming: Exam 3 Preview