Variables in Java

  • A variable is a container which holds the value.
  • Variable is a name of memory location.
  • It is a combination of "vary + able" that means its value can be changed.

Types of Variables

  1. Local variable
  2. Instance variable
  3. Static variable

Local Variable

A variable declared inside the body of the method.
It cannot be defined with "static" keyword.

Instance Variable

A variable declared inside the class but outside the body of the method, is called instance variable. It is not declared as static.

Static Variable

A variable which is declared as static.
It cannot be local.
You can create a single copy of static variable and share among all the instances of the class.
Memory allocation for static variable happens only once.

Example :

class A
{  
    int data=50;      //instance variable  
    static int m=100;     //static variable  
void method()
  {  
    int n=90;     //local variable  
  }  
}//end of class