In this example, we have a list of integers that we want to sort in ascending order. We use theCollections.sort()method to sort the list, and then print the sorted list to the console. The output shows the list sorted in ascending order. This is a basic way to sort a list in Jav...
If you are working on Java 8 or higher version then you can take advantage of stream API to sort an ArrayList. Here, we are using the sorted() method of the stream that helps to sort stream elements. import java.util.ArrayList; import java.util.stream.Collectors; public class Main { pu...
Use the DepartmentComparator to Sort Elements in Java Modify the Program Above Using the lambda Function in Java 8 This article defines what a sort comparator in Java is and demonstrates how you can use it in processes. We’ve included programs you can follow to help you understand this ...
1.2 Sorting ArrayList in Descending Order in Java Now that you knowhow to sort ArrayList in ascending order, it's time to sort the given ArrayList into descending order. For that, we'll use the overloaded version of theCollections.sort()method, which accepts a Comparator. ...
If we need to sort HashMap, we do it explicitly according to the required criteria. We can sort HashMaps by keys or by value in Java. Sort a HashMap by Keys in Java Using the keys, we can sort a HashMap in two ways: aLinkedHashMapor aTreeMap. ...
2. Using JavaStreams Since Java 8,Map.Entryclass has astaticmethodcomparingByKey(), which returns aComparatorcomparing the Map entries in the natural order of keys. ThisComparatorcan be used withStream.sorted()method to sort the stream ofMapentries. ...
importjava.util.stream.Stream;publicclassMain{publicstaticvoidmain(String[]args){Stream<Integer>numStream=Stream.of(1,3,5,4,2);numStream.sorted().forEach(System.out::println);}} Program output. Output 12345 3.2. Descending Order To sort in reverse order, useComparator.reverseOrder()insorted...
etc. In order to sort an ArrayList of custom or user-defined objects, you need two things, first a class to provide ordering and a method to provide sorting. If you know about ordering and sorting in Java then you know that theComparableandComparatorclass is used to provide the ordering ...
To sort a Map<Key, Value> by values in Java, you can create a custom comparator that compares the values and pass it to the sort() method of the Map.Entry class.
We introduced the notion of a Comparator in Java, which is used to specify the sort order of a particular class. Let's start with an example to sort Strings by their length. We thus want to write a Comparator that compares Strings. So the general format of our Comparator will be as ...