Post on 15-Jul-2015
ASSIGNED TO:
SYED MUHAMMAD UMAIR SHAH ROLL NO. 12
MUHAMMAD FARHAN ROLL NO. 06
ABDUL HANAN ROLL NO. 02
WAQAS AZIZ ROLL NO. 05
MALIHA KHAN ROLL NO. 38
AZRA RAMZAN ROLL NO. 45
SYEDA IRAM ALI ROLL NO. 46
BS(CS) 2ND SEMESTER
INDUS INTERNATIONAL INSTITUTE D.G.KHAN
DATA TYPES
In C++ , data are mainly divided into three
different types. These are:
1. Character data type
2. Integer data type
3. Float data type
Data type
A data type defines a set of values and a set of operation on those values. A C++ program may need to required different type of data. Each type required different type of memory.
It indicates the type of data that can be storein a variable
There are three basic data type.
Character
Integer
Float
This data type is used to store character values.
Characters may include letters, digits and
punctuation character. It take one byte in
memory i.e. ‘a’ and ‘@’ etc
Represented by the “char” data type.
Character data type
Character data type:
The “short” data type is the same size as “ char” usually one byte.
The character variable can store only one character
The Character range is “-128 to 127”
We can declared it as below.
Char a=‘A’
Char f=‘B’
Char z=‘D’ etc.
2. Integer data type:
A numeric value with no fraction is called integer data. It include both positive and negative values.
Represented by “int”
Int range –32,768 to 32,767
Some example of integer value are 56 and -12
Int size is ‘2’ bytes
Long int size ‘4’ bytes
We can declared it as below.
Int a=20;
Int b=40;
Int c=30;
Type of Integer data type
Int
Long int
Int data type
To store integer values and takes two byte in memory. i.e. int num;
Long int data type
To store large integer value. It has greater range and takes ‘4’ bytes in memory. i.e. long int num;
3: Float data type:
A numeric value with fraction is called real data type / float data type. It include both positive and negative values. i.e. 12.4 and -34.3
This data type are represented by “float”.
Float number are declared as
Float a=“40.00”
Float b=“23.04”
Float c=“10.3” etc
Type of float
Float
Double
Float data type
This data type is used to store real values and takes ‘4’ bytes in memory. i.e. Float num;
Double data type
It has great range as compared to float and takes ‘8’ byte in memory. i.e. Double num;
Variable
A quantity whose values may change during the execution of the program is called variable.
It may be a numeric or non-numeric quantity
It represented by an identifier called variable name
A variable represents a memory location in the computer memory. Data is store into the memory location. The name of memory location or variable name remains fixed during the execution of the program but the data store in that location may change from time to time
Variable Declaration
A variable is case sensitive, that is, uppercase variables
are treated differently
Variable “SUM” is different from variable “sum”
Variable “NetPay” is different from variable “NETpay”
A variable cannot be the same as
Float X
Elwin
Main X
ping
Dote
Printf X
Rules for variable Declaration
Variable may include letter, number and
underscore(_)
The first latter of the variable must be
character or underscore.
Blank spaces special symbols, commas are
not used
A variable can be ‘31’ character long for many
compilers
Key word are not used as variable name.
Variable Declaration
The process of specifying the name and it’s
data type is called variable declaration
All variables that are used in a program are
declared using variable declaration statement.
When a variable is declared a certain number
of bytes in the memory are allocated to the
variable name.
Syntax
Data- type variable name;
Example
Int num;
In this example variable num is declared which have integer data type
Char name;
In this example variable name is declared which have character data type
Float num;
In this example variable num is declared which have float data type
Variable initialization
The process of assigning a value to a variable at the time of declaration is known as variable initialization.
The equal ( = ) is used to initialize a variable.
Variable name is given on the left side and value is given on the right side of equal sign.
Syntax
Type- name variable = value
Type name : it indicate the data type of variable
Variable : it is the name of variable
Value : it indicate the value initialize to variable.
Example:
Int num=5;
In this example variable num is declared which can have integer data type and contain the value ‘5’.
Char name =‘a’;
In this example variable name is declared which can have character data type and contain the value ‘a’.