Example<\/strong><\/strong><\/p>\n package test;import java.util.*;public class Main {public static void main(String[] args) {List<String> list = new ArrayList<>();list.add(“Rahul”);list.add(“Rohan”);list.add(“Megha”);\/\/ Verify if list contains a specific element or notSystem.out.println(list.contains(“Suraj”));System.out.println(list.contains(“Megha”));Map<Integer, String> hashmap = new HashMap<>();hashmap.put(1, “Arsenal”);hashmap.put(2, “ManU”);hashmap.put(3, “ManCity”);\/\/ Verify if map contains a specific key\/value or notSystem.out.println(hashmap.containsKey(4));System.out.println(hashmap.containsKey(1));System.out.println(hashmap.containsValue(“Real Madrid”));System.out.println(hashmap.containsValue(“Arsenal”));}}<\/p>\n Output falsetruefalsetruefalsetrue<\/span><\/p>\n We can reverse the ArrayList using reverse() method of Collections class.Example<\/strong><\/p>\n import java.util.*;public class Main {public static void main(String[] args) {\/\/Creating an ArrayList object ArrayList < String > arrlist = new ArrayList < String > ();\/\/Adding elements to ArrayList object arrlist.add(“Nokia”);arrlist.add(“Samsung”);arrlist.add(“iPhone”);arrlist.add(“One+”);\/\/Displaying ArrayList Before Reverse System.out.println(“Before Reverse ArrayList:”);System.out.println(arrlist);\/*Reversing the list using Collections.reverse() method*\/Collections.reverse(arrlist);\/\/Displaying list after reverse System.out.println(“After Reverse ArrayList:”);System.out.println(arrlist);}}OutputBefore Reverse ArrayList: [Nokia, Samsung, iPhone, One + ]After Reverse ArrayList: [One + , iPhone, Samsung, Nokia]<\/span><\/p>\n Using ArrayList & LinkedList constructor which takes a collection as an argument, we can convert ArrayList to LinkedList & vice versa.<\/p>\n import java.util.*;public class Main {public static void main(String[] args) {LinkedList < String > linkedlist = new LinkedList < String > ();linkedlist.add(“Mango”);linkedlist.add(“Banana”);linkedlist.add(“Pear”);linkedlist.add(“Apple”);linkedlist.add(“Orange”);\/\/ Converting LinkedList to ArrayListArrayList < String > list = new ArrayList < String > (linkedlist);System.out.println(list);\/\/ Converting ArrayList to LinkedListList < String > list1 = new LinkedList < String > (list);System.out.println(list);}}Output[Mango, Banana, Pear, Apple, Orange][Mango, Banana, Pear, Apple, Orange]<\/span><\/p>\n There are 2 ways we can achieve that. First, sorting the collection and getting the first & last elements of the collection. Second, using max() & min() methods of Collections class, we can get the highest and lowest values.<\/p>\n Example<\/strong><\/p>\n import java.util.*;public class Main {public static void main(String[] args) {LinkedList < Integer > list = new LinkedList < Integer > ();list.add(44);list.add(11);list.add(22);list.add(33);\/\/Sort the collection and get the first and last elementCollections.sort(list);System.out.println(list.get(0));System.out.println(list.get((list.size() – 1)));\/\/Use max() and min() methods of COllections classsSystem.out.println(Collections.max(list));System.out.println(Collections.min(list));}}Output11444411<\/span><\/p>\n A read-only Collection means a Collection where we cannot perform modifications like add, remove or set. We can only read from the Collection by using get method or by using Iterator.<\/p>\n This kind of Collection is good for a certain requirement where parameters are final and cannot be changed.<\/p>\n In Java, we can use Collections.unModifiableList() method to create read-only List , Collections.unmodifiableSet() for creating read-only Set like read-only HashSet and similarly creating a read-only Map in Java, as shown in below example. Any modification in the read-only List will result in java.lang.UnSupportedOperationException. Example<\/strong><\/p>\n import java.util.*;public class Main {public static void main(String[] args) {{List<String> stuff = Arrays.asList(new String[] { “a”, “b” });List<String> list = new ArrayList<>(stuff);list = Collections.unmodifiableList(list);Set<String> set = new HashSet<>(stuff);set = Collections.unmodifiableSet(set);Map<String, String> map = new HashMap<>();map = Collections.unmodifiableMap(map);System.out.println(“Collections are read-only now.”);}}}<\/p>\n The below table summarizes the properties of different collection classes and their properties with respect to duplicate values, null value allowed\/not allowed, sorting and preserving the insertion order.<\/p>\n Write a Program to check if an element is part of a collection or not. We can use contains() function to check if an element is part of any collection apart from Map. For Map type collections, we need to containsKey() to find if a key is present in the map and containsValue() to find […]<\/p>\n","protected":false},"author":1,"featured_media":893,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[21],"tags":[],"class_list":["post-623","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-interview-questions","post-wrapper","thrv_wrapper"],"_links":{"self":[{"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/623","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/comments?post=623"}],"version-history":[{"count":7,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/623\/revisions"}],"predecessor-version":[{"id":631,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/posts\/623\/revisions\/631"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/media\/893"}],"wp:attachment":[{"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/media?parent=623"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/categories?post=623"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rahulshettyacademy.com\/blog\/index.php\/wp-json\/wp\/v2\/tags?post=623"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Write a program to reverse an ArrayList.<\/h3>\n
Write a program to convert ArrayList to LinkedList and vice versa.<\/h3>\n
How to get the highest and lowest values of a List?<\/h3>\n
How to make a collection read-only?<\/h3>\n
What is the difference between Iterator & Enumerator?<\/h3>\n
<\/p>\n
Compare different Collection classes with respect to their properties.<\/h3>\n
<\/p>\n
List<\/h3>\n
What are the differences between List & Set?<\/h5>\n
<\/p>\n
<\/h5>\n
What are the differences between Array and ArrayList?<\/h5>\n
<\/h5>\n
What are the differences between Arraylist & LinkedlList?<\/h5>\n
<\/h5>\n
Set<\/h3>\n
What are the differences between Set & Map?<\/h5>\n
<\/h5>\n
<\/h5>\n
What are the differences between HashSet & TreeSet?<\/h5>\n
<\/h5>\n
Map<\/h3>\n
What are the differences between HashSet & HashMap?
<\/h5>\n
What are the differences between HashMap & TreeMap?<\/h5>\n
<\/h5>\n","protected":false},"excerpt":{"rendered":"