Introduction to variables and data types using c++ and java

1. Variables and Data types

2. Variables
 Variables are analogous to Buckets or Envelopes where
information can be stored.
 We call buckets by names so Variables must have
names for calling.
 Information stored in Variables can also be changed.
 Name of the variable is anything your name also.

3. Data Types
 Data types tell about what type of value our variable
want to store
 It may be INT FLOAT DOUBLE CHAR STRING
 Int:-It will take only integer value no value after
decimal point
 Float:-It will take values after decimal point but has
less precison also known as floating point.
 Double:-Also called floating point because decimal
points flaot more precise than float

4. Data Types Continued
 Char:-It only takes a character it is one byte only takes
only character
 For examples
 Int =10
 Float=10.232
 Double=10.32322
 Char =‘d’
 Char =‘+’

5. Assignment Operator
 Assignment operator “=“ is used to assign value to a
variable
 Beware not used this “==“ be cause it is equality
operator it checks the equality between variable name
and value assigned to it.
 Syntax will be
 Data type variable name assignment operator value

6. Variable Names
 It is up to you what name you give to your variables
 For examples
 Int number=10;
 First DATA TYPE is INT as it only accept integer which is 10
 Second name of our variable is NUMBER name could be
anything here I used Number you can use your name also
 Third Assignment operator we give our variable Number a
value so after this
 Number=10 our variable number can store an integer
number 10.

7. Some Examples
 Int number=10;
 Int bob=20;
 Int khan=30;
 Float num=10.87;
 Float numbe=10.8;
 Double num1=10.2321;
 Double khan=10.43434;

8. Some Examples
 Char name=‘c’;
 Char ali=‘d’;
 Char sign=‘+’;
 Char bob=‘-’
 Char mult=‘*’;
 Note(we will discuss strings later it is also a data type i
will create full slides on strings)

9. Key Points For Char
 Char variable can be of 1 byte means it contain only
only character
 Char name=‘d’; TRUE
 Char name=‘d+’ FALSE
 Char sign=‘++’ FALSE
 Char sign=‘+’ True
 Always use this ‘’ for values

10. Comments
 Always use comments it is good programming pratice
 The benefit of commenting is that some one who sees
your code can easily understand it
 For comments use
 //this is my prog//
 Compiler can execute your programme line by line and
ignore the comments line it does not effect your
programme performance
 Use //I am a commnet//

11. Simple Example
In C++ In Java
 #include<iostream>
 using namespace std;
 int main()
 {
 int
number=10,number1=20,add;//i
nitialize variable and assign
values//
 add=number+number1;//result
of these will be stored in add//
 cout<<add;//for displaying//
 }
 Thanks to Devc++
 public class JavaApplication6 {
 /**
 * @param args the command line
arguments
 */
 public static void main(String[]
args) {
 int number=10,number1=20,add;
 add=number+number1;
 System.out.println(add);
 }

 }
 Thanks to netbeans

12. Thanks alot
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