1. Fundamentals of Computer and programming in C
Rohit Khokher

2. Programming in C Data Types History of C Constants Importance of C
Symbolic class
Variables
Declarations
A variable as a constant
A variable as volatile
Storage class
Data overflow & underflow
History of C
Importance of C
Structure of C Programs
Character Set, tokens, key words & identifiers.
Self study
Self study
Already covered

3. Character Set, tokens, key words & identifiers.
Letters (Uppercase A-Z, Lowercase a-z)
Digits 0-9
Special characters
Comma
Period
Semicolon
Colon
Question mark
Apostrophe
Quotation mark
Exclamation mark
Vertical bar
Slash
Backlash
Tilde
Under score
Dollar , . ; : ? ‘ “ ! | / \ ~ _ $
Percent sign
Caret
Asterisks
Minus sign
Plus sign
Less than
Greater than
Left parenthesis
Right parenthesis
Left brace
Right brace
Number sign
Left bracket
Right bracket % ^ * - +
<
> ( ) { } # [ ]
Equal
WHITE SPACES
Blank space
Horizontal tab
Carriage Return
New line
Form feed =

4. Tokens Operators Keywords Identifiers Constants Strings
Special symbols
+, -, *, /, …
Numeric constants like
Character constants like “Year 2010”
“Year 2010”
Variable names symbolizing memory addresses.
Rules for creating identifiers
The first character must be an alphabet or underscore.
Must consists of letters, digits, or underscore
May have 256 characters but only the first 31 characters are important
Should be a keyword
Should contain white spaces
[. ]. {. }. (. …
Words with fixed meaning. Must be written in lower case.
Example: main, int, float …

5. Tokens key words or reserve words (Prepare a list of ANSI C Key words)
Constants
Numeric
Character
Single
String
Integer
Real
Backslash
‘\a’ bell sound
‘\f’ backspace
‘\n’ new line
‘\t’ horizontal tab
…..
Decimal, Octal and Hexadecimal

6. Example Integer Values 3276 -32768 -32759
#include <stdio.h> void main { printf (“Integer values \n\n”); printf (“%d %d %d \n”, 32767, , ); printf (“\n”); }
Output
Integer Values
Why negative?

7. void Data Types Primary Data Types integer Character floating Point
Signed
-128 to 127
Unsigned
0 to 255
floating Point
signed
unsigned
Int
short int
long int
unsigned int
unsigned short int
unsigned long int
float
Double
Long double
Exercise: Find the size and range of each data type

8. Variable Declaration Data Type Keyword Declaration in C
Character (8 bits)
char
char a, b, c;
Unsigned Character
unsigned char
unsigned char a, b, c;
Signed Character
signed char
signed char a, b, c;
Integer (16 bits)
int
int x, y, z;
Short Integer (8 bits)
short int
short int x, y, z;
Long Integer (32 bits)
long int
long int x, y, z;
Real (32 bits)
float
Float x,y,z;
Real (64 bits)
double
double x, y, z;
Real (89 bits)
long double
Long double x, y, z;

9. Example # include <stdio.h> float x, y; int code;
Data Segment
# include <stdio.h>
float x, y;
int code;
short int count;
long int amount;
double deviation;
unsigned n;
char c;
/* */
Main () { }
x: 4 Bytes
y; 4 Bytes
code; 2 Byte
count; 1 Bytes
amount; 4 Bytes
deviation; 8 Bytes
n; 2 Bytes
c; 1 Byte

10. User defined Data types
typedef
User can define type using typedef feature.
Example
typedef int unit;
typedef float marks;
Unit symbolizes int and marks float.
unit x, y, z; means x, y and z are integer type.
float a, b, c; means a, b, and c are float type.

11. User defined data type enum (enumerated type) Example
enum identifier ( value1, value2, …, valuen)
Example
Definition
enum day (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday);
Variable Declaration
enum day week_st, week_end;
These declaration day week_st and week_end can take values in (Monday to Sunday) and we can use them as
week_st = Monday;
week_end=Friday;

12. Storage Class Location and visibility of variables.
# include <stdio.h>
float x, y;
void main () {
int i;
float b;
- - -
functionx (); }
float functionx ();
float s;
Data segment
Global
x, y are visible to
Main and functionx x y i b i s
Local to main
The variables i and b are
visible to main only
Local functionx
The variables i and s are
visible to functionx only

13. Storage class and their meaning
auto : known within the function it is declared.
static: a local variable that retains its velue even after the control is transferred to calling program.
extern: global variable known to all functions.
register: a local variable that is stored in a register.

14. Assigning values to variables
Assignment statement
Assignment statement is defined as
identifier = expression where expression give a value.
Example
fee = 20.5;
rent = 56;
expense = fee + rent;

15. Programing example # include <stdio.h> void main() { float x, p;
double y, q;
unsigned k;
int m=54321;
long int n= ;
x = ;
y= ;
k= 54321;
P=q=1.0;
printf (“ m = %d \n”, m);
printf (“ n = %ld \n”, n);
printf (“ x = %.121f \n”, x);
printf (“ x = %f \n”, x);
printf (“ y = %.121f \n”, y);
printf (“ y = %f \n”, y);
printf (“ k = %u p = %f q = %.121f \n”, k,p,q); }

16. Defining Synbolic Constants
#define directives
#define PI 3.14
#define PASS_MARK 50
#define MAX = 100
#define STRENGTH 200