w3resource

Java Collection: Exercises, Practice, Solution

Java Collection Exercises [126 exercises with solution]

[An editor is available at the bottom of the page to write and execute the scripts. Go to the editor]

List of Java Collection Exercises :

Java Collection: ArrayList Exercises [22 exercises with solution]

1. Write a Java program to create an array list, add some colors (strings) and print out the collection.
Click me to see the solution

2. Write a Java program to iterate through all elements in an array list.
Click me to see the solution

3. Write a Java program to insert an element into the array list at the first position.
Click me to see the solution

4. Write a Java program to retrieve an element (at a specified index) from a given array list.
Click me to see the solution

5. Write a Java program to update an array element by the given element.
Click me to see the solution

6. Write a Java program to remove the third element from an array list.
Click me to see the solution

7. Write a Java program to search for an element in an array list.
Click me to see the solution

8. Write a Java program to sort a given array list.
Click me to see the solution

9. Write a Java program to copy one array list into another.
Click me to see the solution

10. Write a Java program to shuffle elements in an array list.
Click me to see the solution

11. Write a Java program to reverse elements in an array list.
Click me to see the solution

12. Write a Java program to extract a portion of an array list.
Click me to see the solution

13. Write a Java program to compare two array lists.
Click me to see the solution

14. Write a Java program that swaps two elements in an array list.
Click me to see the solution

15. Write a Java program to join two array lists.
Click me to see the solution

16. Write a Java program to clone an array list to another array list.
Click me to see the solution

17. Write a Java program to empty an array list.
Click me to see the solution

18. Write a Java program to test whether an array list is empty or not.
Click me to see the solution

19. Write a Java program for trimming the capacity of an array list.
Click me to see the solution

20. Write a Java program to increase an array list size.
Click me to see the solution

21. Write a Java program to replace the second element of an ArrayList with the specified element.
Click me to see the solution

22. Write a Java program to print all the elements of an ArrayList using the elements' position.
Click me to see the solution

Java Collection: LinkedList Exercises [26 exercises with solution]

1. Write a Java program to append the specified element to the end of a linked list.
Click me to see the solution

2. Write a Java program to iterate through all elements in a linked list.
Click me to see the solution

3. Write a Java program to iterate through all elements in a linked list starting at the specified position.
Click me to see the solution

4. Write a Java program to iterate a linked list in reverse order.
Click me to see the solution

5. Write a Java program to insert the specified element at the specified position in the linked list.
Click me to see the solution

6. Write a Java program to insert elements into the linked list at the first and last positions.
Click me to see the solution

7. Write a Java program to insert the specified element at the front of a linked list.
Click me to see the solution

8. Write a Java program to insert the specified element at the end of a linked list.
Click me to see the solution

9. Write a Java program to insert some elements at the specified position into a linked list.
Click me to see the solution

10. Write a Java program to get the first and last occurrence of the specified elements in a linked list.
Click me to see the solution

11. Write a Java program to display elements and their positions in a linked list.
Click me to see the solution

12. Write a Java program to remove a specified element from a linked list.
Click me to see the solution

13. Write a Java program to remove the first and last elements from a linked list.
Click me to see the solution

14. Write a Java program to remove all elements from a linked list.
Click me to see the solution

15. Write a Java program that swaps two elements in a linked list.
Click me to see the solution

16. Write a Java program to shuffle elements in a linked list.
Click me to see the solution

17. Write a Java program to join two linked lists.
Click me to see the solution

18. Write a Java program to copy a linked list to another linked list.
Click me to see the solution

19. Write a Java program to remove and return the first element of a linked list.
Click me to see the solution

20. Write a Java program to retrieve, but not remove, the first element of a linked list.
Click me to see the solution

21. Write a Java program to retrieve, but not remove, the last element of a linked list.
Click me to see the solution

22. Write a Java program to check if a particular element exists in a linked list.
Click me to see the solution

23. Write a Java program to convert a linked list to an array list.
Click me to see the solution

24. Write a Java program to compare two linked lists.
Click me to see the solution

25. Write a Java program to check if a linked list is empty or not.
Click me to see the solution

26. Write a Java program to replace an element in a linked list.
Click me to see the solution

Java Collection: HashSet Exercises [12 exercises with solution]

1. Write a Java program to append the specified element to the end of a hash set.
Click me to see the solution

2. Write a Java program to iterate through all elements in a hash list.
Click me to see the solution

3. Write a Java program to get the number of elements in a hash set.
Click me to see the solution

4. Write a Java program to empty an hash set.
Click me to see the solution

5. Write a Java program to test if a hash set is empty or not.
Click me to see the solution

6. Write a Java program to clone a hash set to another hash set.
Click me to see the solution

7. Write a Java program to convert a hash set to an array.
Click me to see the solution

8. Write a Java program to convert a hash set to a tree set.
Click me to see the solution

9. Write a Java program to find numbers less than 7 in a tree set.
Click me to see the solution

10. Write a Java program to compare two hash set.
Click me to see the solution

11. Write a Java program to compare two sets and retain elements that are the same.
Click me to see the solution

12. Write a Java program to remove all elements from a hash set.
Click me to see the solution

Java Collection: TreeSet Exercises [16 exercises with solution]

1. Write a Java program to create a tree set, add some colors (strings) and print out the tree set.
Click me to see the solution

2. Write a Java program to iterate through all elements in a tree set.
Click me to see the solution

3. Write a Java program to add all the elements of a specified tree set to another tree set.
Click me to see the solution

4. Write a Java program to create a reverse order view of the elements contained in a given tree set.
Click me to see the solution

5. Write a Java program to get the first and last elements in a tree set.
Click me to see the solution

6. Write a Java program to clone a tree set list to another tree set.
Click me to see the solution

7. Write a Java program to get the number of elements in a tree set.
Click me to see the solution

8. Write a Java program to compare two tree sets.
Click me to see the solution

9. Write a Java program to find numbers less than 7 in a tree set.
Click me to see the solution

10. Write a Java program to get the element in a tree set which is greater than or equal to the given element.
Click me to see the solution

11. Write a Java program to get the element in a tree set less than or equal to the given element.
Click me to see the solution

12. Write a Java program to get the element in a tree set strictly greater than or equal to the given element.
Click me to see the solution

13. Write a Java program to get an element in a tree set that has a lower value than the given element.
Click me to see the solution

14. Write a Java program to retrieve and remove the first element of a tree set.
Click me to see the solution

15. Write a Java program to retrieve and remove the last element of a tree set.
Click me to see the solution

16. Write a Java program to remove a given element from a tree set.
Click me to see the solution

Java Collection: PriorityQueue Exercises [12 exercises with solution]

1. Write a Java program to create a priority queue, add some colors (strings) and print out the elements of the priority queue.
Click me to see the solution

2. Write a Java program to iterate through all elements in the priority queue.
Click me to see the solution

3. Write a Java program to add all the elements of a priority queue to another priority queue.
Click me to see the solution

4. Write a Java program to insert a given element into a priority queue.
Click me to see the solution

5. Write a Java program to remove all elements from a priority queue.
Click me to see the solution

6. Write a Java program to count the number of elements in a priority queue.
Click me to see the solution

7. Write a Java program to compare two priority queues.
Click me to see the solution

8. Write a Java program to retrieve the first element of the priority queue.
Click me to see the solution

9. Write a Java program to retrieve and remove the first element.
Click me to see the solution

10. Write a Java program to convert a priority queue to an array containing all its elements.
Click me to see the solution

11. Write a Java program to convert a Priority Queue element to string representations.
Click me to see the solution

12. Write a Java program to change priorityQueue to maximum priority queue.
Click me to see the solution

Java Collection: HashMap Exercises [12 exercises with solution]

1. Write a Java program to associate the specified value with the specified key in a HashMap.
Click me to see the solution

2. Write a Java program to count the number of key-value (size) mappings in a map.
Click me to see the solution

3. Write a Java program to copy all mappings from the specified map to another map.
Click me to see the solution

4. Write a Java program to remove all mappings from a map.
Click me to see the solution

5. Write a Java program to check whether a map contains key-value mappings (empty) or not.
Click me to see the solution

6. Write a Java program to get a shallow copy of a HashMap instance.
Click me to see the solution

7. Write a Java program to test if a map contains a mapping for the specified key.
Click me to see the solution

8. Write a Java program to test if a map contains a mapping for the specified value.
Click me to see the solution

9. Write a Java program to create a set view of the mappings contained in a map.
Click me to see the solution

10. Write a Java program to get the value of a specified key in a map.
Click me to see the solution

11. Write a Java program to get a set view of the keys contained in this map.
Click me to see the solution

12. Write a Java program to get a collection view of the values contained in this map.
Click me to see the solution

Java Collection: TreeMap Exercises [26 exercises with solution]

1. Write a Java program to associate the specified value with the specified key in a Tree Map.
Click me to see the solution

2. Write a Java program to copy Tree Map's content to another Tree Map.
Click me to see the solution

3. Write a Java program to search for a key in a Tree Map.
Click me to see the solution

4. Write a Java program to search for a value in a Tree Map.
Click me to see the solution

5. Write a Java program to get all keys from a Tree Map.
Click me to see the solution

6. Write a Java program to delete all elements from a Tree Map.
Click me to see the solution

7. Write a Java program to sort keys in a Tree Map by using a comparator.
Click me to see the solution

8. Write a Java program to get a key-value mapping associated with the greatest key and the least key in a map.
Click me to see the solution

9. Write a Java program to get the first (lowest) key and the last (highest) key currently in a map.
Click me to see the solution

10. Write a Java program to get a reverse order view of the keys contained in a given map.
Click me to see the solution

11. Write a Java program to get a key-value mapping associated with the greatest key less than or equal to the given key.
Click me to see the solution

12. Write a Java program to get the greatest key less than or equal to the given key.
Click me to see the solution

13. Write a Java program to get the portion of a map whose keys are strictly less than a given key.
Click me to see the solution

14. Write a Java program to get the portion of this map whose keys are less than (or equal to, if inclusive is true) a given key.
Click me to see the solution

15. Write a Java program to get the least key strictly greater than the given key. Return null if there is no such key.
Click me to see the solution

16. Write a Java program to get a key-value mapping associated with the greatest key strictly less than the given key. Return null if there is no such key.
Click me to see the solution

17. Write a Java program to get the greatest key strictly less than the given key. Return null if there is no such key.
Click me to see the solution

18. Write a Java program to get a NavigableSet view of keys in a map.
Click me to see the solution

19. Write a Java program to remove and get a key-value mapping associated with the least key in a map.
Click me to see the solution

20. Write a Java program to remove and get a key-value mapping associated with the greatest key in this map.
Click me to see the solution

21. Write a Java program to get the portion of a map whose keys range from a given key (inclusive) to another key (exclusive).
Click me to see the solution

22. Write a Java program to get the portion of a map whose keys range from a given key to another key.
Click me to see the solution

23. Write a Java program to get a portion of a map whose keys are greater than or equal to a given key.
Click me to see the solution

24. Write a Java program to get a portion of a map whose keys are greater than a given key.
Click me to see the solution

25. Write a Java program to get a key-value mapping associated with the least key greater than or equal to the given key. Return null if there is no such key.
Click me to see the solution

26. Write a Java program to get the least key greater than or equal to the given key. Returns null if there is no such key.
Click me to see the solution

Java Practice online

More to Come !

Do not submit any solution of the above exercises at here, if you want to contribute go to the appropriate exercise page.



Follow us on Facebook and Twitter for latest update.

Java: Tips of the Day

Capturing an exception's stack trace 

import java.io.*;

Exception e = ...;
java.io.StringWriter sw = new java.io.StringWriter();
e.printStackTrace(new java.io.PrintWriter(sw));
String trace = sw.getBuffer().toString();

Ref: https://bit.ly/3k8PmGm

 

We are closing our Disqus commenting system for some maintenanace issues. You may write to us at reach[at]yahoo[dot]com or visit us at Facebook