Java Program to Perform Set Operations

Set in java-

•       The set interface is  present in the java.util  package. It extends the Collection interface.

•       It is an unordered collection of objects in which duplicate values are not allowed.

•        It is an interface which can implements the mathematical set.

•       This interface contains the methods inherited from the Collection interface and adds a feature to restricts the insertion of the duplicate elements.

•       The set interface allows the users to perform the basic mathematical set operations as following.

•        Intersection: This operation returns all the common elements from the given two sets.

•       Union: This operation adds all the elements in one set with the other. 

•       Difference: This operation removes all the values present in one set from the other set.

        --------------------------------------------------Program------------------------------------------------------

/**

 *

 * @author Shikha

 */

import java.util.*; 

public class SetExample 

{ 

public static void main(String args[]) 

{       int ans=0;

                char ch='n';

Set<String> a = new HashSet<String>(); 

                a.add("Mumbai");

                a.add("Delhi");

                a.add("Chennai");

                a.add("Calcutta");

                a.add("Bengaluru");    

                a.add("Hyderabad");

                Set<String> b = new HashSet<String>(); 

                b.add("Mumbai");

                b.add("Delhi");

                b.add("Chennai");

                b.add("Calcutta");

                b.add("Bengaluru");  

b.add("Pune");  

                b.add("Indore");  

               

                          

               Scanner sc=new Scanner(System.in);

               //System.out.print(" 1:Union\t 2:Insertion\t 3:Difference\t 4:Stop");

                do{

                System.out.println(" 1:Union\t 2:Insertion\t 3:Difference\t 4:Stop");    

                ans=sc.nextInt();   

                    

                switch(ans)

                {

                

                    case 1:

                    Set<String> union = new HashSet<String>(a); 

                    union.addAll(b); 

                    System.out.println("Union of the two Set"); 

                    System.out.println(union);

                    break;

                    

                    case 2:

                    Set<String> intersection = new HashSet<String>(a); 

                    intersection.retainAll(b); 

                    System.out.println("Intersection of the two Set"); 

                    System.out.println(intersection);       

                    break;

                    

                    

                    case 3:

                    Set<String> difference = new HashSet<String>(a); 

                    difference.removeAll(b); 

                    System.out.println("Difference of the two Set"); 

                    System.out.println(difference); 

                    break;

                    

                    default:

                    System.out.println("Wrong Choice");   

                    

                            

                }

                

                System.out.println("Do you want to continue Y/N");

                ch=sc.next().charAt(0); 

                }while((ch=='y')||(ch=='Y'));

} 

} 

------------------------------------------------------------------------------------------------------------------------

OUTPUT

 1:Union 2:Insertion 3:Difference 4:Stop

1

Union of the two Set

[Delhi, Calcutta, Chennai, Bengaluru, Pune, Indore, Mumbai, Hyderabad]

Do you want to continue Y/N

y

 1:Union 2:Insertion 3:Difference 4:Stop

2

Intersection of the two Set

[Delhi, Calcutta, Chennai, Bengaluru, Mumbai]

Do you want to continue Y/N

y

 1:Union 2:Insertion 3:Difference 4:Stop

3

Difference of the two Set

[Hyderabad]

Do you want to continue Y/N

n

Java Program using Array to implement CRUD-Create,Read ,Update and Delete Operations.

import java.util.*;

public class Main

{

static Scanner sc = new Scanner(System.in);

public static void main(String[] args)

{

int[] arr = new int[20];

int ans,len;

len = create(arr);

do

{

System.out.println("\n\nSelect \n1.Insert\t2.Delete\t3.Search\t4.Update\t5.Display\t6.Stop\n");

ans=sc.nextInt();

switch (ans)

{

case 1:

System.out.println("Enter no to insert");

int num = sc.nextInt();

arr[len]=num;

len++;

break;

case 2:

System.out.println("Enter Element TO Delete");

int del = sc.nextInt();

int D = search(arr, len, del);

if(D != -1)

{for (int i = D; i < len-1; i++)

arr[i] = arr[i+1];

len--;

System.out.println("Delete Succesful");

}

else

System.out.println("Element not found");

break;

case 3:

System.out.println("Enter Element TO be searched");

int ele = sc.nextInt();

int s = search(arr, len, ele);

if(s != -1)

System.out.println("Element "+ele+" present at "+s);

else

System.out.println("Element not found");

break;

case 4:

System.out.println("Enter Element TO be Updated");

int up1 = sc.nextInt();

int U = search(arr, len, up1);

if(U != -1)

{

System.out.println("Enter Replacing element");

int up2=sc.nextInt();

arr[U]=up2;

System.out.println("Update Successful");

}

else

System.out.println("Element not found");

break;

case 5:

display(arr,len);

break;

case 6:

System.out.println("Thank You!");

break;

default:

System.out.println("Wrong chice");

break;

}

} while (ans != 6);

}

public static int create(int arr[])

{

System.out.println("Enter the length of string");

int n = sc.nextInt();

System.out.println("Enter "+ n +" numbers");

for(int i =0 ; i<n ;i++)

arr[i]=sc.nextInt();

return n;

}

public static void display(int arr[],int len)

{

System.out.println("Array elements are");

for (int i = 0; i <len; i++)

System.out.print(arr[i]+"\t");

System.out.println("");

}

public static int search(int arr[],int len,int ele)

{

for (int i = 0; i < len; i++)

if(arr[i] == ele)

return i;

return -1;

}

}

************************************Output**************************************

********************************************************************************

Enter the length of string

4

Enter 4 numbers

12

13

14

15

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

1

Enter no to insert

11

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

5

Array elements are

12 13 14 15 11

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

2

Enter Element TO Delete

11

Delete Succesful

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

5

Array elements are

12 13 14 15

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

4

Enter Element TO be Updated

14

Enter Replacing element

11

Update Successful

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop

5

Array elements are

12 13 11 15

Select 

1.Insert 2.Delete 3.Search 4.Update 5.Display 6.Stop