This document contains lecture notes for a C programming course offered at the Higher Technological Institute. The course covers topics such as program development, C essentials, operators, input/output, decision making, iteration, arrays, functions and more across 9 chapters. The notes provide examples and explanations of C concepts like data types, variables, expressions, arithmetic operators, statements and more. Code snippets are included to demonstrate printing characters and performing arithmetic operations on integers.

1. LOGO
Higher Technological Institute
10th of Ramadan City
6th of October Branch
Electrical and Computer Engineering Department
Lecture Notes in
Prepaid By: Eng. Ibrahim Elewah
Main Reference
HTI Student Book and “C For Dummies”
by Dan Gookin 2nd Edition
1

2. Course Contents
1
Introduction
2
Program Development
3
The Essential of C Programs
4
Manipulating Data with Operators
5
Reading from and Writing to Standard I/O
6
Decision
7
Iteration
8
Arrays
9
C Functions
C Programming
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3. Course Contents
3
The Essential of C Programs
 Constants and variables
 Expressions
 Arithmetic operators
 Statements
 Statement blocks
 Data Types and Names in C
 Naming a Variable
C Programming
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4. Expressions
o An expression is a combination of constants,
variables, and operators that are used to
denote computations
𝑨= 𝟐∗ 𝑨 − 𝟏
1. Taking the value contained in the drawer
(variable) A
2. Multiply this value by 2
3. Subtract 1 from result obtained from 2
4. The value contained in drawer A is omitted, then
putting the result obtained from 3 into drawer A.
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5. Arithmetic Operations
Addition
Subtraction
Multiplication
Division
Reminder
The Reminder operator % is used to obtain
the reminder of the first operand divided by
the second operand
C Programming
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6. Arithmetic Operations
Addition
Subtraction
Multiplication
Division
Reminder
Example
𝟔% 𝟒= 𝟐
C Programming
𝟏𝟎𝟎𝟏%𝟐 = 𝟏
6
𝟒𝟖%𝟓 =
Higher Technological Institute

7. Arithmetic Operations
Addition
Subtraction
Multiplication
Division
Reminder
Example
𝟔% 𝟒= 𝟐
C Programming
𝟏𝟎𝟎𝟏%𝟐 = 𝟏
7
𝟒𝟖%𝟓 = 𝟑
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8. Constants and Variables
o As its name implies, a constant is a value that never
changes.
o A variable, on the other hand, can be used to present
different values.
o For instance, consider the following:
𝒊 = 𝟏 ;
o Where the symbol i is a constant because it always has
the same value (1) and the symbol i is assigned the
constant 1.
o In other words, i contains the value of 1 after the
statement is executed.
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9. Data Types and Names
o The C language reserves some keywords
words that have special meanings to the
language.
o Those reserved words should not be used
as variables, constants, or function names
in your program.
o All C keywords must be written in
lowercase letters, for instance INT will not
be treated as a keyword, it must be written
as int.
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10. The computer list of C keywords
auto
const
double
float
int
short
struct
unsigned
C Programming
break
continue
else
for
long
signed
switch
void
case
default
enum
goto
register
sizeof
typedef
volatile
10
char
do
extern
if
return
static
union
while
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11. Naming a Variable
Valid Variable Name Can Use
o Characters A through Z and a through z
o Digit characters 0 through 9, which can be
used in any position except the first of a
variable name.
o The underscore character _
Examples
stop_sign
C Programming
loop3
11
and_pause
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12. Naming a Variable
Invalid Variable Name Can NOT be Used
o
o
o
o
A variable name can’t contain any C arithmetic signs.
A variable name can’t contain any dots.
A variable name can’t contain any apostrophes.
A variable name can’t contain any other special
symbols such as *, @, #, and so on.
Examples
4flags
return
C Programming
sum-result
what_size?
12
method*4
ahmed.ali
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13. Data Types
C Data Type
char
int
float
double
a, B, $, #
5, 17, 128
2.5 , 0.3
23433.3455
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14. Declaration Statement
Type
Name Value
char
int
float
double
c1
N1
F1
d1
char c1
= ‘&’ ;
int
‘&’
100
32/10
5e3
= 100 ;
n1
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15. Declaration Statement
Type
char
int
float
double
Name Value
‘&’
100
32/10
5e3
c1
N1
F1
d1
char c1
;
c1
= ‘&’ ;
int
;
n1
= 100 ;
n1
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16. Declaration Statement
Type
Name Value
char
int
float
double
float
c1
n1
f1
d1
‘&’
100
32/10
5e3
f1= 32/100 ;
double
C Programming
d1=5e3 ;
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17. Declaration Statement
Type
Name Value
char
int
float
double
‘&’
100
32/10
5e3
c1
n1
f1
d1
float
f1
;
f1
=
32/100 ;
double
d1 ;
d1
=
5e3
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;
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18. Some special characters in C
b
Backspace
f
Form feed
n
New line
r
Return
t
Tab
C Programming
Moves the cursor to the left
one character
Goes to the top of a new
page
Carriage return and line
feeds
Returns to the beginning of
the current line
Advances to the next tab
stop
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19. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
char c2;
/* declaration of the character variable c2 */
c1 = ‘A’; /* assigning c1 with the character constant A */
c2 = ‘a’; /* assigning c2 with the character constant a */
return 0;
}
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20. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
char c2;
/* declaration of the character variable c2 */
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
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21. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
printf ( “ The character c1 is : variablen */”, c1);
%c c2
char c2;
/* declaration of the character
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
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22. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
printf ( “ The character c1 is : variablen */”, c1);
%c c2
char c2;
/* declaration of the character
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
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23. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
printf ( “ The character c1 is : variablen */”, c1);
%c c2
char c2;
/* declaration of the character
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
C Programming
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24. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
printf ( “ The character c1 is : variablen */”, c1);
%c c2
char c2;
/* declaration of the character
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
New Line
Specifier
for
Character Data Type
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25. Examples
/* Example1 : Printing out characters */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 13 */
char c1;
/* declaration of the character variable c1 */
char c2;
/* declaration of the character variable c2 */
c1 = ‘A’;
/* assigning c1 with the character constant A */
c2 = ‘a’;
/* assigning c2 with the character constant a */
printf ( “ The character c1 is : %c n ”, c1);
printf ( “ The character c1 is : %c ” , c1);
printf ( “ while the character c2 is : %c n”, c2);
return 0;
}
C Programming
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26. You Have To Know about Data Types
Type
Name
Value
Specifier
char
c1
‘&’
%c
int
n1
100
%d
float
f1
32/10
%f
double
d1
5e3
%e,%E
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27. Examples
/* The arithmetic operations on integers */
# include<stdio.h>
/* the header file for the printf () function */
main ( )
{
/* the main function body till line 15 */
int m = 3;
int n=2;
printf ( "The summation of %d and %d is : %d.n", m, n, m+n);
printf ( "The difference between %d and %d is : %d.n", m, n, m-n);
printf ( "The multiplication of %d by %d is : %d.n", m, n, m*n);
printf ( "The division of %d by %d is : %d.n", m, n, m/n);
printf ( "The remainder of division of %d by %d is : %d.n", m, n, m%n);
return 0 ;
}
C Programming
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28. Operators Precedence
Operator Sign
( )
/
*
+
-
C Programming
Name
Brackets
Division
Multiplication
Addition
Subtraction
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29. Logic Operators
Operator Sign
||
&&
!=
C Programming
Name
OR
AND
NOT
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30. Examples
/* Example3 : Integer vs. floating point divisions */
# include <stdio.h>
/* the header file for the printf ()
function */
main ( )
{
int n1,n2,n3;
float m1,m2,m3;
n1 = 32/10;
m1= 32/10;
n2 = 32.0/10;
m2= 32.0/10;
n3 = 32/10.0;
m3 = 32/10.0;
return 0;
}
C Programming
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31. Examples
/* Example3 : Integer vs. floating point divisions */
# include <stdio.h>
/* the header file for the printf () function */
main ( )
{
int n1,n2,n3;
float m1,m2,m3;
n1 = 32/10;
m1= 32/10;
n2 = 32.0/10;
m2= 32.0/10;
n3 = 32/10.0;
m3 = 32/10.0;
printf ( “ The integer division of 32/10 is :
%d n”, n1);
printf ( “The floating point division of 32/10 is :
%f n”, m1);
printf ( “The integer division of 32.0/10 is :
%d n”, n2);
printf ( “The floating point division of 32.0/10 is :
%f n”, m2);
printf ( “The integer division of 32/10.0 is :
%d n”, n3);
printf ( “The floating point division of 32/10.0 is :
%f n”, m3);
return 0;
}
C Programming
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32. Double Data Type
o Here are two examples:
[mantissa] e [exponent]
[mantissa] E [exponent]
Example
5000
-300
0.0025
5e3.
-3e2
2.5e-3.
Specifier %e or %E
With printf ( )
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33. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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34. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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35. Precedence Example
# include<stdio.h>
X(
B/C + A ;
main = ) E * D –
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
C Programming
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36. Precedence Example
X= E*D –
X= E*D –
C Programming
B/C
B/C
+ A ;
+ A ;
36
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37. Precedence Example
X= E*D –
C Programming
B/C + A ;
37
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38. Precedence Example
X= E*D –
B/C + A ;
A = 20
B=6
C=3
D = 10
E=2
C Programming
( )
*
/
+-
38
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39. Precedence Example
X= E*D –
2 * 10 –
A = 20
B/C + A ;
6 / 3 + 20
B=6
C=3
D = 10
E=2
C Programming
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( )
*
/
+-
Higher Technological Institute

40. Precedence Example
X= E*D –
2 * 10 –
A = 20
B=6
C=3
D = 10
E=2
C Programming
20
B/C + A ;
6 / 3 + 20
–
2
40
+ 20
( )
*
/
+-
Higher Technological Institute

41. Precedence Example
X= E*D –
2 * 10 –
A = 20
B=6
C=3
D = 10
E=2
C Programming
20
B/C + A ;
6 / 3 + 20
–
2
38
41
+ 20
( )
*
/
+-
Higher Technological Institute

42. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
C Programming
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43. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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44. Precedence Example
# include<stdio.h>
main = )( E * D ) – ( B / C ) + A ;
Y (
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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45. Precedence Example
Y=(E*D)–(B/C)+ A ;
.
.
.
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46. Precedence Example
Y=(E*D)–(B/C)+ A ;
.
.
.
38
C Programming
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47. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
C Programming
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48. Precedence Example
# include<stdio.h>
Z( = A * ( D – B ) / ( C + E ) ;
main )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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49. Precedence Example
Z= A*(D–B)/(C+ E);
A = 20
B=6
C=3
D = 10
E=2
C Programming
( )
*
/
+-
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50. Precedence Example
Z= A*(D–B)/(C+ E);
A = 20
B=6
C=3
D = 10
E=2
C Programming
( )
*
/
+-
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51. Precedence Example
Z= A*(D–B)/(C+ E);
A = 20
B=6
C=3
D = 10
E=2
C Programming
20 *
4
/
51
5
( )
*
/
+-
Higher Technological Institute

52. Precedence Example
Z= A*(D–B)/(C+ E);
A = 20
B=6
C=3
D = 10
E=2
C Programming
20 *
4
/
16
52
5
( )
*
/
+-
Higher Technological Institute

53. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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54. Precedence Example
# include<stdio.h>
main ( )
{
int A,B,C,D,E, X, Y, Z;
A = 20 ; B = 6 ;
C = 3 ; D = 10 ; E = 2 ;
X= E*D – B/C + A ;
Y=(E*D)–(B/C)+ A ;
Z= A*(D–B)/(C+ E);
printf ( “ X= %d n Y= %d n Z=%d n”, X,Y,Z);
return 0 ;
}
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55. Home Work ..!!
Exercises 3 Page 44
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56. LOGO
Higher Technological Institute
10th of Ramadan City
6th of October Branch
Electrical and Computer Engineering Department
Eng. Ibrahim Elewah
Main Reference
HTI Student Book and “C For Dummies”
by Dan Gookin 2nd Edition
56