Inheritance basic program


1:- 




 class Demo
{
      void animal ()
      {
      System.out.println("it is parent class");

      }

}
class childDemo extends Demo{

    void Dog()
    {
       System.out.println("this is a child class");
    }
    public static void main(String arg[])
    {
        Demo s1= new Demo();
        s1.animal();
        Ager mai dog method ko call kar to yah pe error aa jata kuki me Demo class ka
obj create kiya hai
    }
}
C:\java>javac Testing.java

C:\java>java childDemo
it is parent class

C:\java>

 

2:-



 class Demo
{
      void animal ()
      {
      System.out.println("it is parent class");

      }

}
class childDemo extends Demo{

    void Dog()
    {
       System.out.println("this is a child class");
    }
    public static void main(String arg[])
    {
        childDemo s1= new childDemo();
        s1.animal();
        s1.Dog();
// yha pe error nahi aya hai ki childDemo class ke obj create kiya the
or usko inherate kiya hua hai
       
    }
}

C:\java>javac Testing.java

C:\java>java childDemo
it is parent class
this is a child class

C:\java>


 

3:_

class Demo
{
      void animal ()
      {
      System.out.println("it is parent class");

      }

}
class childDemo {      

    void Dog()
    {
       System.out.println("this is a child class");
    }
    public static void main(String arg[])
    {
        childDemo s1= new childDemo();
       // s1.animal();
        s1.Dog();
    }
}
C:\java>javac Testing.java

C:\java>java childDemo
this is a child class

C:\java>
yha pe error nahi aya kuki childclass ke obj banaya or or usi class ke ander ke method call kiya

 

3:-

class Demo
{
      void animal ()
      {
      System.out.println("it is parent class");

      }

}
class childDemo {      

    void Dog()
    {
       System.out.println("this is a child class");
    }
    public static void main(String arg[])
    {
        Demo s1= new Demo();
       s1.animal();
        //s1.Dog();
    }
}

C:\java>javac Testing.java

C:\java>java childDemo
it is parent class

C:\java>


yha pe error nahi aya kuki childclass ke obj banaya or or usi class ke ander ke method call kiya

4:- 

class Demo
{
    static void method ()
    {
        System.out.println("hello world");
    }
   
}
class Demo2 extends Demo{
   
     void mehtod2 ()
    {
        System.out.println(" hello2");
    }
       
    public static void main(String args[])
    {
       
        Demo2.method(); // is program me without obj create parent class me method
                                 call liya hua hai
    }
       
}

C:\java>javac Testing.java

C:\java>java Demo2
hello world

C:\java>



5:-

class Demo
{
    static void method ()
    {
        System.out.println("hello world");
    }
   
}
class Demo2 extends Demo{
   
     void mehtod2 ()
    {
        System.out.println(" hello2");
    }
       
    public static void main(String args[])
    {
       
        Demo.method();
       
    }
       
}

Output

C:\java>javac Testing.java

C:\java>java Demo2
hello world

C:\java>



6:- 

class Demo
{
    static void method ()
    {
        System.out.println("hello world");
    }
   
}
class Demo2 extends Demo{
   
     static  void method2 ()
    {
        System.out.println(" hello2");
    }
       
    public static void main(String args[])
    {
       
        Demo.method(); //yha pe first function ko call kiya hua hai
        Demo2.method2(); // secend function ko call kiya hua hai
       
    }
       
}

C:\java>javac Testing.java

C:\java>java Demo2
hello world
 hello2

C:\java>




6:-

class Demo
{
    static void method ()
    {
        System.out.println("hello world");
    }
   
}
class Demo2 { //yha pe inherate ke jarural hi nahi pari
                    kuki donal class ko call kiya hua hia or method bhi
   
     static  void method2 ()
    {
        System.out.println(" hello2");
    }
       
    public static void main(String args[])
    {
       
        Demo.method();
        Demo2.method2();
       
    }
       
}

C:\java>javac Testing.java

C:\java>java Demo2
hello world
 hello2

C:\java>





7:-
class Demo
{
    static void method ()
    {
        System.out.println("hello world");
    }
   
}
class Demo2 extends Demo {
   
     static  void method2 ()
    {
        System.out.println(" hello2");
    }
       
    public static void main(String args[])
    {
       
        Demo2.method();
        Demo2.method2();
       
    }
       
}

C:\java>javac Testing.java

C:\java>java Demo2
hello world
 hello2

C:\java>













































































































3:-

class Hello
{
// Declare an instance block.
   {
      show();
   }
Hello() // constructor
{
   System.out.println("Hello constructor");
   show();
}
   void show()
   {
   System.out.println("Hello method");
    }
}


class mytest{
  public static void main(String args[])
  {
    Hello obj = new Hello();
    obj.show();
 
  }
  }
  OUTPUT
//   C:\java>javac Testing.java

// C:\java>java mytest
// Hello method
// Hello constructor
// Hello method
// Hello method

4:-

class Hello
{
// Declare an instance block.
   {
      show();
   }
Hello()     //constructor
{
   System.out.println("Hello constructor");
   show();   //method
}
void show()  //method
{
   System.out.println("Hello method");
 }
}
class Hi extends Hello
{
   Hi() //constructor
   {
      System.out.println("Hi constructor");
   }
void show() { // Override the show() method.
     System.out.println("Hi method");
  }
}
 class TestHelloHi extends Hi
{
  public static void main(String[] args)
  {
     Hi obj = new Hi();
      obj.show(); // show() method of Hi class is called.
 
 
  }
}

OUTPUT

C:\java>javac Testing.java

C:\java>java TestHelloHi
Hi method
Hello constructor
Hi method
Hi constructor
Hi method

5:-

 class Hello
{
// Declare an instance block.
   {
      show();
   }
Hello()     //constructor
{
   System.out.println("Hello constructor");
   show();   //method
}
void show()  //method
{
   System.out.println("Hello method");
 }
}
class Hi extends Hello
{
   Hi() //constructor
   {
      System.out.println("Hi constructor");
   }
void show() { // Override the show() method.
     System.out.println("Hi method");
  }
}
 class TestHelloHi extends Hi
{
  public static void main(String[] args)
  {
     // Superclass reference is equal to child class object.
     Hello obj1 = new Hi();
      obj1.show();
 
 
  }
}

//OUTPUT

C:\java>javac Testing.java

C:\java>java TestHelloHi
Hi method
Hello constructor
Hi method
Hi constructor
Hi method

C:\java>

6:-

8:-















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