2. Data Type
• A data type defines a set of values that a
variable can store along with a set of
operations that can be performed on that
variable.
• Common data types are integer, character,
and real.
5. Data Type
• Basic Data type(Primary, fundamental)
• Integers, Character and Floating point
Primary Data type
Integer
Singed type
Unsigned type
int
unsigned int
short int
unsigned short int
long int
unsigned long int
Character
Signed char
Unsigned char
float
Floating Point
double long double
6. Data Type
• Basic Data type(Primary, fundamental)
• Integers
• Signed and unsigned types
Integer
Singed type
Unsigned type
int
unsigned int
short int
unsigned short int
long int
unsigned long int
• Signed– can store + and –ve integers
• Unsigned– can store only +ve integers
7. Data Type
• Basic Data type(Primary, fundamental)
• Signed type integers
• int :- integers are whole numbers, capable to
storing numeric value without decimal places.
• any number in the range -32768 to 32767
• It occupies 2 bytes of memory
• Long int :- required 4 bytes of memory.
• Value range from -2147483648 to 2147483647
• Long int variable can declare
• long int a,b; or long a;
8. Data Type
• Basic Data type(Primary, fundamental)
• Signed type integers
• Short integers :- need less space in memory (same
as int)
• Short int variable can delare
• short int a; or int a;( both are same)
9. Data Type
• Basic Data type(Primary, fundamental)
• Unsigned integers
• unsigned integers :- some time if we know in advanced,
the value stored in an integer variable is always be +ve.
• Such situations we can declared the variable as
unsigned int
• The range permissible integer value will shift from 0 to
65535 ie double the size of int
• Unsigned integer variable can declare
• unsigned int a; or unsigned a;( both are same)
10. Data Type
• Basic Data type(Primary, fundamental)
•
•
•
•
Unsigned integers
unsigned short integers :- same as unsigned int
unsigned long integers :Range 0 to 42949672954 (double size of long int)
• Unsigned long integer variable can declare
• unsigned long int a;
11. Data Type
• Basic Data type(Primary, fundamental)
• Characters
•
•
•
•
•
•
•
•
Character
Signed and unsigned types
Signed char
Both occupy 1 byte of memory
Unsigned char
But having different range
Signed char is same as ordinary char and has range 128 to 127
Unsigned char range from 0 to 255
Example
cnsigned char a;
char a;
12. Data Type
• Basic Data type(Primary, fundamental)
• Floating point
•
•
•
•
•
•
float
Floating Point
double long double
A float variable occupy 4 bytes of memory
Range from 3.4E-38 to 3.4E+38
Double occupy 8 bytes of memory
Range from 1.7E-308 to 1.7E+308
Long double occupy 10 bytes of memory
Range from 3.4E-4932 to 3.4E+4932
13. Data Type
Type
char
unsigned char
int
unsigned int
short int
long int
unsigned long int
float
double
long double
size (bytes)
1
1
2
2
2
4
4
4
8
10
Range
127 to -128
0 to 255
32768 to -32767
0 to 65535
32768 to -32767
2147483648 to - 2147483647
0 to 4294967295
3.4E-38 to 3.4E+38
1.7E-308 to 1.7E+308
3.4E-4932 to 3.4E+4932
14. Data Type
•
•
•
•
•
User Defined Data type
User Defined Data Type
Type Definition
Enumerated datatype
Structure
Union
Type Definition
Enumerated datatype
Structure
Union
15. Data Type
• User Defined Data Type
• Type Definition
• Allows user to define an identifier that would
represent an existing data type
• This identifier can later used to declared
variables
typedef type identifier
• syntax:-• Eg: typedef int integet;
• integer a;
16. Data Type
• User Defined Data Type
• Enumerated
• Allows user to declare variables can have one
value enclosed within braces.
• Way of attaching name to numbers
• syntax:-- enum identifier {value1, value2, …..};
• Eg: enum sex{male,female};
• Then value of male=0 and female=1
17. Data Type
• User Defined Data Type
• Structure
• A structure is a collection of one or more variables, possibly of
different types, grouped together under a single name
A structure is defined by the keyword struct followed by a
set of variables enclosed in braces.
Consider the following structure to represent a person’s details.
struct Personnel {
char name[100];
int age;
double height;
};
The variables name, age and height are called members of the
structure type Personnel.
18. Data Type
• User Defined Data Type
• Structure
There are two ways to define variables of a particular structure
type.
1. Declare them at the structure definition.
struct Personnel {
char name[100];
int age;
double height;
} p1, p2, p3; /* Define 3 variables */
2. Define the variables at some point after the structure
definition.
struct Personnel p1, p2, p3; /* Define 3 variables */
19. Data Type
• User Defined Data Type
• Union
• A union is a collection of one or more variables, possibly of
different types, grouped together under a single name
A union is defined by the keyword union followed by
a set of variables enclosed in braces.
Consider the following union to represent a person’s details.
union Personnel {
char name[100];
int age;
double height;
};
The variables name, age and height are called members
of the union type Personnel.
20. Data Type
• User Defined Data Type
• union
There are two ways to define variables of a particular union
type.
1. Declare them at the union definition.
union Personnel {
char name[100];
int age;
double height;
} p1, p2, p3; /* Define 3 variables */
2. Define the variables at some point after the union
definition.
union Personnel p1, p2, p3; /* Define 3 variables */
