Question

data structure class:

a. syntax for generics

b. comparable interface

c.how do you implement interface

answer for all of them please.

answer for all of them please

Answer 1

`Hey,

Note: If you have any queries related the answer please do comment. I would be very happy to resolve all your queries.

1)

Like C++, we use <> to specify parameter types in generic class creation. To create objects of generic class, we use following syntax.

// To create an instance of generic class 
BaseType <Type> obj = new BaseType <Type>()

Note: In Parameter type we can not use primitives like 
      'int','char' or 'double'.

2)

Comparable interface is mainly used to sort the arrays (or lists) of custom objects.
Lists (and arrays) of objects that implement Comparable interface can be sorted automatically by Collections.sort (and Arrays.sort).

For example

 public int compareTo(Author au){
     /* 
      * Sorting by last name. compareTo should return < 0 if this(keyword) 
      * is supposed to be less than au, > 0 if this is supposed to be 
      * greater than object au and 0 if they are supposed to be equal.
      */
     int last = this.lastName.compareTo(au.lastName);
     //Sorting by first name if last name is same d
     return last == 0 ? this.firstName.compareTo(au.firstName) : last;
  }
}

3)

import java.io.*;

  

// A simple interface

interface In1

{

    // public, static and final

    final int a = 10;

  

    // public and abstract

    void display();

}

  

// A class that implements the interface.

class TestClass implements In1

{

    // Implementing the capabilities of

    // interface.

    public void display()

    {

        System.out.println("Geek");

    }

  

    // Driver Code

    public static void main (String[] args)

    {

        TestClass t = new TestClass();

        t.display();

        System.out.println(a);

    }

}

Kindly revert for any queries

Thanks.