Fundamentals of Computing and C Programming - Part 2

Presentation By Karthik Srini
Fundamentals of Computing and C Programming
Unit II - Basics of C language

Seminar II
By Karthik Srini

Synopsis
1. Data Types
2. Type Conversion
3. Type Deﬁnition
4. Control Structures

Data Types
In the C programming language, data types refer to an extensive system
used for declaring variables or functions of different types. The type of a
variable determines how much space it occupies in storage and how the
bit pattern stored is interpreted. They are categorised as :
1. Basic Data Type
2. Enumerated Data Type
3. The void Type
4. Derived Data Type

Basic Data Types
The basic data types in C are :
1. Integer data type
2. Float data type
3. Character data type

Integer Data Type
The integer data types are further classiﬁed as integers and characters.
Integers can be classiﬁed with respect to length and sign as,
• Unsigned Integer
• Signed Integer
• Long Integer
• Short Integer

Signed Integer & Unsigned Integer
The are normally identiﬁed by the sign in front of the integer value. An
integer value without any sign is assumed to be positive. (i.e.)
unsigned.
For example,
unsigned int num = 10 ; ( unsigned )
int num = -10 ; ( signed )

Long Integer
If a large integer value is to be stored in a variable, then long is
preﬁxed before int while declaring the variable.
For example,
If you want to store a mobile number ( 10 digits ), you declare it as ,
long int mobile_number = 1234567891 ;

Short Integer
Short integer is normally used to reduce the size of the program, since
short int occupies less memory space than int and long int .
For example,
short num = 11 ;

Float Data Type
Float data type is normally used to represent floating points ( or )
floating numbers, float is prefixed before the variable name.
For example,
float pi = 3.14 ;

Double Data Type
Double data type is used to represent larger ﬂoating numbers
For example,
double num = 43.66677 ;

Long Double Data Type
Long double data type is used to represent even larger ( or ) longer
ﬂoating numbers.
For example,
long double num = 4167.7789056 ;

Character Data Type
It is usually used to represent characters. The variable name is
preﬁxed by char . Must be enclosed within single quotes.
For example,
char alphabet = ‘ c ’ ;

Fundamentals of Computing and C Programming - Part 2

Enumerated Data Types

Enumerated Data Types
Enumerated data types are user defined data types. They are
predefined with a discrete set of values by the user.
For example,
enum month ( Jan , Feb , Mar , Apr , May , Jun , Jul , Aug , Sep , Oct , Nov , Dec ) ;
enum month first = Jan ;

Type Definition
It is an user defined data type similar to enumerated data types, the
only difference is, in type definition it is not necessary to define the
discrete set of values.
For example,
typedef int number ;
number num1 , num2 ;

The void Data Type
Void means null ( or ) nothing. It is normally preﬁxed before functions.
For now, this information is enough. You will learn in detail in the
forthcoming chapters.

Derived Data Types

Derived Data Types
They include,
(a) Pointer types,
(b) Array types,
(c) Structure types,
(d) Union types and
(e) Function types.

Arrays
Arrays are defined as the collection of variables having the same base type
( or ) data type. Arrays are further classified as :
1. Single Dimensional Array
2. Double Dimensional Array
They are normally declared as like other declarations, but the array index
must be specified.
For example,
int num [5] ;

int num[5];
Memory allocation for
the above array.
0 1 2 3 4
100 34 76 56 89

Type Conversions

Type Conversion
Conversion of values of one data type into another data type is called
Type conversion. It is classiﬁed as :
1. Implicit Type Conversion
2. Explicit Type Conversion

Implicit Type Conversion
These are done by the complier itself, without the knowledge of the
programmer.
For example,
int b = 7 / 2 ; ( value of b will be 4 )

Explicit Type Conversion
This type of conversion are done by the user willingly.
For example,
int pi = (int) 3.4 ;

Functions

Functions
A function is a group of statements that together perform a task. Every
C program has at least one function, which is main(), and all the most
trivial programs can deﬁne additional functions. You can divide up
your code into separate functions.

Function Prototype
In computer programming, a function prototype or function interface is
a declaration of a function that speciﬁes the function's name and type
signature (parameter types, and return type), but omits the function
body.
For example,
int add ( int a , int b )

Control Structures

Control Structures
Control structure decide the way of ﬂow of control in a program. Based
on some test conditions, the control of the program gets jumped from
one point to the other. They can be further classiﬁed as :
1. Selection Statements
2. Looping Statements

Selection Statements
The control of the program gets jumped from one point to the other
based on a test expression. They are classiﬁed as :
1. If else
2. Switch Case

Simple if Syntax
if ( condition )
{
action block ;
}

if else Syntax
if ( condition )
{
Action block 1 ;
}
else
{
Action block 2 ;
}

if , else if , else Syntax
if ( condition )
{
action block 1 ;
}
else if ( condition )
{
action block 2 ;
}
else
{
action block 3 ;
}

Switch Case Syntax
switch ( condition )
{
case 1 :
action block1 ;
break ;
case 2 :
action block2 ;
break ;
default :
action block3 ;
}

Looping Structures

Looping Structures
Looping is a type of control structure in which a set of instructions is
repeated again and again until the test condition evaluates to true.
There are two major types,
1. Entry controlled loop
2. Exit controlled loop

Entry controlled loop
Checks whether the test expression evaluates to true, before the
statements in the loop gets executed. If the test expression evaluates
to false, the loop terminates.
These have two loops in major,
1. For loop
2. While Loop

For loop
For loop has ﬁxed number of repetitions. It is an entry controlled loop.
It consists of three main clauses namely,
1. Initialisation expression
2. Test Expression
3. Update Expression
A for loop can have multiple initialisation expressions and multiple
update expressions but can have only one test expression.

for Loop Syntax
for ( initialisation exp ; test exp ; update exp )
{
action block ;
}

While loop
While loop does not have ﬁxed number of iterations. It is an entry
controlled loop.

while Loop Syntax
initialisation expression ; ( if needed )
while ( condition )
{
action block ;
update expression ; ( if needed )
}

Exit Controlled Loop
Checks whether the test expression evaluates to true, after the
statements in the loop gets executed. It gets executed at least once.
They have one loop in major,
1. Do While loop.

Do While Loop
It is an exit controlled loop. Gets executed at least once.

do while Loop Syntax
initialisation expression ;
do
{
action block ;
update expression ;
}
while ( condition ) ;

Queries ???

Log on to :
www.facebook.com/groups/skcetcsea
For downloading this Powerpoint presentation

Thank You

Fundamentals of Computing and C Programming - Part 2

Recommended

More Related Content

What's hot (20)

Viewers also liked (14)

Similar to Fundamentals of Computing and C Programming - Part 2 (20)

More from Karthik Srini B R (7)

Recently uploaded (20)

Fundamentals of Computing and C Programming - Part 2