#VARIABLES and TYPES#

Published on 10 June 2020

By COMPUTER PROGRAMMING 2020

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Published on 10 June 2020

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Variables and types

A variable is a data name that is used to store the data value. Constant variable cannot be changed during the execution of a program.

A variable is a symbol or name that stands for a value. It is a value that can change. A variable can take different values during the execution. It can be choose by the programmer in many ways.

Example 1:

c = a + b

This is an example of programming expression.

a, b and c are variables.

Example 2:

Average
Total
Count_1
Class_strength

In every program, variable has its own:

·Name (Identifier)

·Data Type

·Size

·Value

Variable consists of letters, digits and the underscore (_) character. It has following conditions:

1 Uppercase and lower case is significant.

For example: The variable Average is not the same as average or AVERAGE

2 They must begin with a letter.

3 It should not be a keyword.

4 White space is not allowed.

Example of valid variable names is:

SUM1 ph_value Mumbai

John Value distance

Example of variable names

Variable Name	Valid?	Remarks
First_tag	Valid
Price$	Not valid	Dollar sign is not valid
Average weight	Not valid	Blank space is not allowed
Int_type	Valid	Keyword may be the part of a name

Variables can represent numeric values, characters, character strings, or memory addresses.

Types of Variables in JAVA

Types of Variables

Local Variables Instance Variables Static Variables

·Local variable- A variable that is declared inside the method that is called local variable.

·Instance variable- A variable that declared the inside the class but outside the method that is called instance variable.

·Static variable-A static Variable is a special type of the variable that is shared by all objects from a class. Static variable are used to keep track of global information such as number of objects from a class

Example1:-

class Simple

{

public static void main(String[] args)

{

int a=10;

int b=10;

int c=a+b;

System.out.println(c);

}

Example2:-

class A