Skip to main content

Static Variable

Static Variable:-A variable which is declared inside class, but outside method with static modifier called static variable. Static variables are used for memory saving purpose or providing facility. Static variable is a class level variable so every object can use static variable and access same value of that variable. So static variable is not related to particular object only. Any object can change the value of static variable and after change every object access new value of variable.static variables can access by two ways one is using the classname.variable and second is object.variable. Static variables can directly access in static method as well as non static method of class.

Example1:- Display default value directly.

class Student
{

static String instName;
public static void main(String[]args)
{
System.out.println(instName);
}
}

Output:-
C:\JAVATECH>javac Student.java
C:\JAVATECH>java Student
Null

Example2:- Display default value using class name.

class Student
{

static String instName;
public static void main(String[]args)
{
System.out.println(Student.instName);
}
}

Output:-
C:\JAVATECH>javac Student.java
C:\JAVATECH>java Student
Null

Example3:-Display default value using object.

class Student
{

static String instName;
public static void main(String[]args)
{
Student s=new Student();
System.out.println(s.instName);
}
}

Output:-
C:\JAVATECH>javac Student.java
C:\JAVATECH>java Student
Null

Example4:-Display initialize value directly.

class Student
{

static String instName="IIT Indore";
public static void main(String[]args)
{
System.out.println(instName);
}
}
Output:-
C:\JAVATECH>javac Student.java
C:\JAVATECH>java Student
IIT Indore

Example5:-object change the initialize value.

class Student
{
static String instName="IIT Indore";
public static void main(String[]args)
{
System.out.println(instName);
Student s=new Student();
s.instName=”IIM Indore”;
Student s1=new Student ();
System.out.println(s1.instName);

}
}

Output:-
C:\JAVATECH>javac Student.java
C:\JAVATECH>java Student
IIT Indore

IIM Indore

Comments

Popular posts from this blog

inheritance

INHERITANCE:- Inheritance is the process of code re-usability, using this property software or applications can develop in less time or can develop rapidly. Inheritance increases the readability of code and decrease redundancy or repetition of code or reduces size of code. Use of previously developed code in future any number of times is called inheritance. Through inheritance variables and methods of class can inherited. Types of Inheritance:- 1)         Single or Single level inheritance 2)         Multilevel inheritance 3)         Hierarchical inheritance Java does not support to multiple inheritance. Single or single level inheritance:- In a single inheritance a class is inherited by a single class. In a single or single level inheritance a sub class having only one super class directly or indirectly. Syntax: -        class Subclass ex...

Inheritance-4

Example10:- class Student { Student() { System.out.println("This is super class Zero argument constructor"); } Student(String s) { System.out.println("This is super class One argument constructor"); } } class Test extends Student { Test() { super(null); System.out.println("This is sub class Zero argument constructor"); } public static void main(String[]args) { Test t=new Test(); } } Output:- C:\JAVATECH>javac Test.java C:\JAVATECH>java Test This is super class One argument constructor This is sub class Zero argument constructor Example11:- class Student { Student() { System.out.println("This is super class Zero argument constructor"); } Student(String s) { System.out.println("This is super class One argument constructor"); } } class Test extends Student { Test() { super(); super(null); System.out.println("This is su...

Abstraction,Encapsulation And Inheritance

Abstraction  is a one of the great feature of Oops,in this feature hide entire details of product, show only requirement specifications(what product will do). The main purpose behind abstraction is to increase productivity or use of product without knowledge of product implementation. in this case the person don't know how product  was implemented but know how product works or action of product. In java abstraction is achieved by abstract class and interface,here interface provide 100% abstraction and abstract class provide partial abstraction. For example: - ATM machine is example of abstraction.  every technical and non-technical person use facility of ATM without knowing the entire process. they know if they click on withdraw button then they can withdraw money from ATM machine but they don't know when they click on withdraw button the request is send to the server and after go into database and so on. Here ATM machine show only requirement specificat...