1. 1-6
Midterm Review

2. Review chapter 1-6
Variables, arithmetic, decision making
Structured program development in C
C program controls
C Functions
C Arrays
Midterm exam rules, scope, and tips

3. 1: Variables, Arithmetic, Decision making
Memory Concepts
Understand variables: type, size, value
Arithmetic in C
Remember the precedence of arithmetic operators
Decision Making: Equality and Relational Operators
Remember the meaning and syntax of equality and relational operators

4. 2: Structured Program Development in C
Basic problem-solving techniques
2 important primary steps
Thorough understanding of the problem
Carefully plan an approach for solving it
Algorithms, Pseudo code, control structures
Formulating Algorithm with Top-down, stepwise refinement case
3 phases programming
Initialization, processing, and termination
Control statements
If…else, while, nested control, counter and sentinel controlled repetition
Operators: assignment, increment, decrement

5. 3: Program control Essential of counter-controlled repetition
Control statements:
Pretest loop: for
Posttest loop: do … while
Multiple selection: switch
Alter flow control:
break
continue
Complex conditional expressions

6. 3.1: Pretest Loop for Syntax: Init: assignments to counter variables
for ( init ;
condition ;
update )
statement;
Init: assignments to counter variables
Update: changes to counter variables

7. 3.1: For Example Printing vertical line of stars: for (counter = 0;
{ printf(“*\n”);}

8. 3.2: Posttest Loop do-while
Syntax:
do {
statement(s)
} while (condition);

9. 3.2: Using the do-while do { printf(“\n Enter id# and salary: “);
scanf(“%d %f”,&id,&salary);
printf(“\n You entered id#%1d”, id);
printf(“ and salary $%.2f,”, salary);
printf(“ Is this correct? (Y/N) ” );
scanf(“ %c”,&ans);
} while ((ans != ‘Y’) && (ans != ‘y’));
Loop always executes at least once

10. 3.3: Multiple selection - Switch
Useful when a variable or expression is tested for all the values it can assume and different actions are taken
Format
Series of case labels and an optional default case
switch ( value ){
case '1':
actions
case '2':
default: }
break; exits from statement

11. 3.4: Break statement The break statement can be used to halt a loop.
do {
scanf(“%d”,&num);
if (num < 0) break; /* Loop ends */
} while (num != 0);

12. 3.5: Continue statement
A continue statement says jump past any remaining statements
Example:
for (I = 0; I < 100; I++) {
if ((I % 2) == 1) continue;
printf(“%d is even”,I);
// continue goes to here: end of
// statements }

13. 3.6: Logical operators

14. 4: C Functions Program modules in C
Function definitions and prototypes
Function call stack and activation records
Headers
Calling function by value and reference
Functions
Math library functions
rand()
Recursion

15. Fig. 5.1 | Hierarchical boss function/worker function relationship.
4.1: Program modules in C
Fig. 5.1 | Hierarchical boss function/worker function relationship.

16. 4.2: Function definition & Prototypes
Function definition format
return-value-type function-name( parameter-list ) { declarations and statements }
Function Prototypes
Function name, Parameters, Return type (default int)
Used to validate functions
Prototype only needed if function definition comes after use in program
int maximum( int x, int y, int z );
Takes in 3 ints
Returns an int

17. 4.3: Function call stack and activation records
Program execution stack:
Last-in, first-out data structure
Keep track of which functions have been called
Activation records:
Multiple function can be activated at the same time
Each function has an activation record (Stack frame)
Stack overflow: # activation records > memory capacity

18. 4.4: Function headers Header files Custom header files
Contain function prototypes for library functions
<stdlib.h> , <math.h> , etc
Load with #include <filename>
#include <math.h>
Custom header files
Create file with functions
Save as filename.h
Load in other files with #include "filename.h"
Reuse functions

19. 4.5: Calling Functions Call by value Call by reference
Copy of argument passed to function
Changes in function do not effect original
Use when function does not need to modify argument
Avoids accidental changes
Call by reference
Passes original argument
Changes in function effect original
Only used with trusted functions

20. 4.6 Storage class Identifier attributes: Storage class specifiers:
Storage duration – how long an object exists in memory
Scope – where object can be referenced in program
Linkage – specifies the files in which an identifier is known
Storage class specifiers:
Automatic storage duration: Auto, Register
Static storage duration: Extern, Static

21. 4.7: Scope rules Identifier scopes: Function scope: File scope:
Can only be referenced inside a function body
Used only for labels (start:, case: , etc.)
File scope:
Identifier defined outside function, known in all functions
Used for global variables, function definitions, function prototypes
Block scope:
Identifier declared inside a block
Local variables of function

22. 4.8: Recursion (1) Recursive functions Recursion vs. Iteration
Functions that call themselves
Can only solve a base case
Recursion vs. Iteration
Repetition
Iteration: explicit loop
Recursion: repeated function calls
Termination
Iteration: loop condition fails
Recursion: base case recognized
Both can have infinite loops

23. 4.8: Recursion (2) Example: factorials Notice that
5! = 5 * 4 * 3 * 2 * 1
Notice that
5! = 5 * 4!
4! = 4 * 3! ...

24. 5: C Arrays Array data structure Passing arrays to functions
Sorting, searching arrays
Multiple-Subscripted arrays

25. 5.1: Array data structure Structure: To refer to an element, specify
Group of consecutive memory locations
Same name and type
To refer to an element, specify
Array name
Position number
Format:
arrayname[ position number ]
Defining arrays
arrayType arrayName[numberOfElements ];

26. 5.2: Passing arrays to functions
Arrays passed call-by-reference
Name of array is address of first element
Syntax:
Function_name ( array_name, array_size );
Passing array elements
Passed by call-by-value
Pass subscripted name (i.e., myArray[ 3 ]) to function
Function prototype
void modifyArray( int b[], int arraySize );

27. 5.3 Sorting & Searching Arrays
Sorting arrays
Bubble sort
Computing: Mean, Median, Mode
Searching arrays
Linear
Binary
Recursive & Interative

28. 5.4: Multiple-Subscripted arrays
Tables with rows and columns (m by n array)
Like matrices: specify row, then column
Initialization
int b[ 2 ][ 2 ] = { { 1, 2 }, { 3, 4 } };
Referencing elements
Specify row, then column

29. Midterm exam rules, scope, & tips
You are not allowed to refer to any materials except one cheating paper.
The examination starts at 9:00 AM and ends at 10:30AM sharp.
You can leave any time if you want before 10:30PM.
Scope: Chapter 1-6
Tips:
Review all lecture slides
Review all class assignments and home works
Do all Self-Review exercises after each chapter in text book
Practice as many as possible