Collections in Java Practical Programs

Collections in Java

• What is List in Java ?

Represents an ordered collection. Lists can contain duplicate elements.

• What is SortedSet in Java ?

Represents a set whose elements are maintained in a sorted order. 

• What is Set in Java ?

Represents an unordered collection that does not permit duplicate elements.

• What is Queue in Java ?

A collection used to hold multiple elements prior to processing. A Queue provides additional insertion, extraction and inspection operations.

• What is Map in Java ?

Represents key-value pairs. A Map cannot contain duplicate keys; each key can map to at most one value. Does not extend collection.

• What is Sorted Map in Java ?

Represents a Map that maintains its mappings in ascending key order

• What is Collection in Java ?

The most general collection interface type. A collection represents a group of objects known as its elements. The Java platform doesn't provide any direct implementations of this interface. 

Accept ‘n’ integers from the user and store them in a collection. Display them in the sorted order. The collection should not accept duplicate elements.Search for an particular element using predefined search method in the Collection framework. 

Program :

import java.util.*;
import java.io.*;

class codingexpert10
{
            public static void main(String[] args) throws Exception
            {
                        int no,element,i;
                        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
                        TreeSet ts=new TreeSet();
                        System.out.println("Enter the of elements :");
                        no=Integer.parseInt(br.readLine());
                        System.out.println("Enter elements");
                        for(i=0;i<no;i++)
                        {
                                                
                             element=Integer.parseInt(br.readLine());
                             ts.add(element);
                        }
                       
                                    System.out.println("The elements in sorted order :"+ts);       
                        System.out.println("Enter element to be serach : ");
                        element = Integer.parseInt(br.readLine());
                        if(ts.contains(element))
                                    System.out.println("Element is found");
                        else
                                    System.out.println("Element is NOT found");
            }
}

Output :

codingexpert10@kali-linux:~/Desktop/Ty$ javac codingexpert10.java

Note: codingexpert10.java uses unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

codingexpert@kali-linux:~/Desktop/Ty$ java codingexpert10 

Enter the of elements :
3
Enter elements
1
2
3
The elements in sorted order :[1, 2, 3]
Enter element to be serach : 
3
Element is found