Best Programming Channel. What is variable and its types, Clear Your Con...

Variables

The variable in Java is a memory location which used to stores the data values during Java program execution. Every variable has a data type that defined the type and quantity of data that hold data. variable used to store data temporarily. The name of the variable cannet be changed but the value of the variable.

Declaration of variables in java

Syntax 

 type        Variable Name  = Value;

       ↘                            ↘ variable name 

     Data type like int,             Like a,b

     string, char

Example 1:

     Create a variable called the ’ Student Name’ of type String and assign it the value "Ahmad Mukhtiar":  

String Student Name =” Ahmad Mukhtiar”;  

System.out.println(“Student Name”,+Student Name);

  Example 2:

Create a variable called ‘Roll No’ of type int and assign it 50: 

int Roll No=50;

System.out.println(“Your Roll No “+Roll No);   

Example 3:

You can assign value later declare a variable without assigning a value

Int a ;

a=10;

System.out.println(The value of a=”+a);

You can assign a new value to exist it will overwrite the previous value

Int a=40;

a=30;

System.out.println(“overwrite the value is “,+a);

Types of Variables 

There are their types of variable

1)Instance variable

2)Static variable 

3)Local variable 

1)Instance Variable 

A variable declared outside the method but inside the class is called instance variable 

It not declared with the static keyword.

2)Static variable

A variable declared with a static keyword is called a static variable.

A single copy of a static variable can  you create and share among all the instance of the class 

When class is loaded in memory at this time static variable happens.

3)Local Variable

A type of variable that declared inside the method is called local 

Variable. You can access the local variable only inside the method.

You cannet use the “static” keyword with the local variables.

To Visit the fellowing programming for better understating.

Programs No1.

Class A{

Int a=20;

Static int b=50;

Void method()

{

Int c=40;

system.out.println(“Sum of instance ,static and local variable are =”+a+b+c);

}

Public static void main(String[]  args){

method();

}

}

Programs NO 2:

1. Class ADD{  
2. public static void main(String[] args){  
3. int y=100;  
4. int x=40;  
5. int z=y+x;  
6. System.out.println(z);  
7. }}