Skip to main content

Interface-5

Example16:-    TestMain.java

interface A
{
void disp();
}
class Test implements A
{
public void disp()
{
System.out.println("Implemented method");
}
}
class TestMain
{
public static void main(String[]args)
{
Test t=new Test();
t.disp();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
Implemented method

Example17:-    TestMain.java

interface A
{
void disp();
}
class Test implements A
{
public void disp()
{
System.out.println("Implemented method");
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test();
t.disp();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
Implemented method
Explanation: - we cannot create object of interface but interface reference variable can hold object of implemented class.


Example18:-    TestMain.java

interface A
{
void disp();
}
class Test implements A
{
public void disp()
{
System.out.println("Implemented method");
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test();
t.disp();
}
}

Output:-
C:\JAVATECH>javap TestMain
Compiled from "TestMain.java"
class TestMain {
  TestMain();
  public static void main(java.lang.String[]);
}
C:\JAVATECH>javap Test
Compiled from "TestMain.java"
class Test implements A {
  Test();
  public void disp();
}

Example19:-    TestMain.java

interface A
{
void disp();
void show();
}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method ");
}
}
class Test2 implements A
{
public void show()
{
System.out.println("Implemented show method ");
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test();
t.disp();
t.show();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
TestMain.java:13: error: Test2 is not abstract and does not override abstract method disp() in A class Test2 implements A
^
1 error
Explanation: -Implemented class must override all interface methods.

Example20:-TestMain.java

interface A
{
void disp();
void show();
}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method ");
}
}
class Test2 extends Test1
{
public void show()
{
System.out.println("Implemented show method ");
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test1();
t.disp();
t.show();
}
}
Output:-
C:\JAVATECH>javac TestMain.java
TestMain.java:24: error: Test1 is abstract; cannot be instantiated
A t=new Test1();
    ^
1 error
Explanation: -Implemented class must override all interface methods otherwise class must be abstract and remaining all abstract method must be overridden in the next level extended class.

Example21:-TestMain.java

interface A
{
void disp();
void show();
}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method ");
}
}
class Test2 extends Test1
{
public void show()
{
System.out.println("Implemented show method ");
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test1();
t.disp();
t.show();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
Implemented disp method
Implemented show method

Example22:-TestMain.java

interface A
{
int a=100;
void disp();
void show();
}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method Value of a="+a);
}
}
class Test2 extends Test1
{
public void show()
{
System.out.println("Implemented show method Value of a="+a);
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test2();
System.out.println("In main method Value of a="+t.a);
t.disp();
t.show();
}
}
Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
In main method Value of a=100
Implemented disp method Value of a=100
Implemented show method Value of a=100


Example23:-TestMain.java

interface B
{
int a=100;
void disp();
void show();
}
interface A extends B
{

}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method Value of a="+a);
}
}
class Test2 extends Test1
{
public void show()
{
System.out.println("Implemented show method Value of a="+a);
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test2();
System.out.println("In main method Value of a="+t.a);
t.disp();
t.show();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
In main method Value of a=100
Implemented disp method Value of a=100
Implemented show method Value of a=100

Example24:-TestMain.java

interface B
{
int a=100;
void disp();
}
interface A extends B
{
void show();
}
abstract class Test1 implements A
{
public void disp()
{
System.out.println("Implemented disp method Value of a="+a);
}
}
class Test2 extends Test1
{
public void show()
{
System.out.println("Implemented show method Value of a="+a);
}
}
class TestMain
{
public static void main(String[]args)
{
A t=new Test2();
System.out.println("In main method Value of a="+t.a);
t.disp();
t.show();
}
}

Output:-
C:\JAVATECH>javac TestMain.java
C:\JAVATECH>java TestMain
In main method Value of a=100
Implemented disp method Value of a=100
Implemented show method Value of a=100


Comments

Post a Comment

Popular posts from this blog

Introduction of Java

Java is a high level programming language which is used for creating various types of software's or applications. Types of java applications:- 1)     Stand alone application 2)     Desktop based application          3)     Web based application 4)     Enterprise application etc. Stand alone application:- Stand alone application run on single machine without user interface and every stand alone application having main method. Desktop based application:- Desktop based application also run on single machine with user interface and every Desktop based application having main method. Web based application:- Web based application run on web, web based application not required main method but for such types of application need server. Enterprise application:- Enterprise application is category of web application where doing some business or involve some money related issues. Java Editions: - There are four Java platforms. ·       
2 comments
Read more

Small concept about OOPs

Some small concept about OOPs:- In many books and website write about OOPs concepts as hundred percent object oriented, pure object oriented and partial object oriented language. Hundred percent object oriented:- In the hundred percent object oriented movie hero is object, without object program is incomplete that means can not execute program without object. Without class and object programming or application development is not possible. Example of hundred percent object oriented language is  Smalltalk . Pure object oriented:- In the object oriented cinema obviously object is the hero. In pure object oriented language object having same importance but in this having some relax that is without creating object we can successfully execute our application. So in the object oriented programming without class we cannot create or run our application, class is must. Example of pure object oriented language is  Java . Partial object oriented:- In this type of language cl
Post a Comment
Read more

java print

Syntax of main method in java is    public static void main(String[]args)  before understanding about main method we have to understand that who is responsible for main method.if we write a simple program or write a simple java class without main method like      Test.java           class Test      {      } above program will compile successfully.for compilation of  java file use  javac tool  or  javac.exe  file. javac Test.java it means compiler checks only syntax of class that means compiler does not check the main method in the file or program,so that compiler is not responsible for main method in java. After successfully compilation of above program we have to run the generated byte code. java Test Error: Main method not found in class Test, please define the main method as:    public static void main(String[] args) So JVM (java virtual machine) or java interpreter is responsible for main method,first jvm check that the main method is pres
Post a Comment
Read more