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1. Top results related to how to sort an array in java

   • How to sort Objects in an Array in Ascending Order in Java?

     Top Answer

     Answered Mar 17, 2014 · 0 votes

     Comparable and Comparator provide 2 different sorting mechanisms. Comparable is useful for Objetcs with a natural ordering, such as words or numbers. For an Employee Object, this might be an employee id.

     Comparator provides a mechanism for sorting Objetcs based on some arbitrary method and allows for Objects to be sorted in many different ways as required.

     Both java.util.Collections and java.util.Arrays provide method for working with Comparable Objects, and sorting using Comparators.

     Your problem is based on sorting Integers, which have natural ordering. Please check the documentation for java.lang.Integer.

     Check all answers on Stack Overflow

     1/5

   • How to sort an array of objects in Java?

     Top Answer

     Answered Sep 28, 2015 · 51 votes

     You have two ways to do that, both use the Arrays utility class

     • Implement a Comparator and pass your array along with the comparator to the sort method which take it as second parameter.
     • Implement the Comparable interface in the class your objects are from and pass your array to the sort method which takes only one parameter.

     Example

     class Book implements Comparable<Book> { public String name, id, author, publisher; public Book(String name, String id, String author, String publisher) { this.name = name; this.id = id; this.author = author; this.publisher = publisher; } public String toString() { return ("(" + name + ", " + id + ", " + author + ", " + publisher + ")"); } @Override public int compareTo(Book o) { // usually toString should not be used, // instead one of the attributes or more in a comparator chain return toString().compareTo(o.toString()); }}@Testpublic void sortBooks() { Book[] books = { new Book("foo", "1", "author1", "pub1"), new Book("bar", "2", "author2", "pub2") }; // 1. sort using Comparable Arrays.sort(books); System.out.println(Arrays.asList(books)); // 2. sort using comparator: sort by id Arrays.sort(books, new Comparator<Book>() { @Override public int compare(Book o1, Book o2) { return o1.id.compareTo(o2.id); } }); System.out.println(Arrays.asList(books));}

     Output

     [(bar, 2, author2, pub2), (foo, 1, author1, pub1)][(foo, 1, author1, pub1), (bar, 2, author2, pub2)]

     Other Answers

     Answered Sep 19, 2013 · 60 votes

     You can try something like this:

     List<Book> books = new ArrayList<Book>();Collections.sort(books, new Comparator<Book>(){ public int compare(Book o1, Book o2) { return o1.name.compareTo(o2.name); }});

     Other Answers

     Answered Feb 08, 2016 · 45 votes

     Java 8

     Using lambda expressions

     Arrays.sort(myTypes, (a,b) -> a.name.compareTo(b.name));

     Test.java

     public class Test { public static void main(String[] args) { MyType[] myTypes = { new MyType("John", 2, "author1", "publisher1"), new MyType("Marry", 298, "author2", "publisher2"), new MyType("David", 3, "author3", "publisher3"), }; System.out.println("--- before"); System.out.println(Arrays.asList(myTypes)); Arrays.sort(myTypes, (a, b) -> a.name.compareTo(b.name)); System.out.println("--- after"); System.out.println(Arrays.asList(myTypes)); }}

     MyType.java

     public class MyType { public String name; public int id; public String author; public String publisher; public MyType(String name, int id, String author, String publisher) { this.name = name; this.id = id; this.author = author; this.publisher = publisher; } @Override public String toString() { return "MyType{" + "name=" + name + '\'' + ", id=" + id + ", author='" + author + '\'' + ", publisher='" + publisher + '\'' + '}' + System.getProperty("line.separator"); }}

     Output:

     --- before[MyType{name=John', id=2, author='author1', publisher='publisher1'}, MyType{name=Marry', id=298, author='author2', publisher='publisher2'}, MyType{name=David', id=3, author='author3', publisher='publisher3'}]--- after[MyType{name=David', id=3, author='author3', publisher='publisher3'}, MyType{name=John', id=2, author='author1', publisher='publisher1'}, MyType{name=Marry', id=298, author='author2', publisher='publisher2'}]

     Using method references

     Arrays.sort(myTypes, MyType::compareThem);

     where compareThem has to be added in MyType.java:

     public static int compareThem(MyType a, MyType b) { return a.name.compareTo(b.name);}

     Check all answers on Stack Overflow

     2/5

   • How to sort an Array of Strings in Java

     Array Of Strings

     To sort an array of strings in Java, we can use Arrays.sort() function.

     Java

     // A sample Java program to// sort an array of strings// in ascending and descending// orders using Arrays.sort(). import java.util.Arrays;import java.util.Collections; // Driver Classpublic class SortExample {      // main method        public static void main(String[] args)    {        String arr[] = { "practice.geeksforgeeks.org",                         "www.geeksforgeeks.org",                         "code.geeksforgeeks.org" };         // Sorts arr[] in ascending order        Arrays.sort(arr);        System.out.printf("Modified arr[] : \n%s\n\n",                          Arrays.toString(arr));         // Sorts arr[] in descending order        Arrays.sort(arr, Collections.reverseOrder());         System.out.printf("Modified arr[] : \n%s\n\n",                          Arrays.toString(arr));    }}

     Output

     Modified arr[] : Modified arr[] : [www.geeksforgeeks.org, practice.geeksforgeeks.org, code.geeksforgeeks.org]

     ArrayList Of Strings

     We have an ArrayList to sort, we can use Collections.sort()

     Java

     // A sample Java program to sort// an arrayList of strings// in ascending and descending// orders using Collections.sort(). import java.util.ArrayList;import java.util.Collections; // Driver Classpublic class SortExample {    // main method    public static void main(String[] args)    {         ArrayList<String> al = new ArrayList<String>();        al.add("practice.geeksforgeeks.org");        al.add("www.geeksforgeeks.org");        al.add("code.geeksforgeeks.org");         // Sorts ArrayList in ascending order        Collections.sort(al);        System.out.println("Modified ArrayList : \n" + al);         // Sorts arr[] in descending order        Collections.sort(al, Collections.reverseOrder()); System.out.println Modified ArrayList n...

     Check all answers on Geeksforgeeks

     3/5

   • How to sort an array in reverse order using java?

     Top Answer

     Answered Apr 07, 2011 · 6 votes

     Collections.reverseOrder() returns a Comparator<Object>. And Arrays.sort with comparator doesn't work for primitives

     This should work

     import java.util.Arrays;import java.util.Collections;-public class MyArray { public static void name() { String hello = "hello, world"; char[] hello_array = hello.toCharArray(); // copy to wrapper array Character[] hello_array1 = new Character[hello_array.length]; for (int i = 0; i < hello_array.length; i++) { hello_array1[i] = hello_array[i]; } // sort the wrapper array instead of primitives Arrays.sort(hello_array1, Collections.reverseOrder()); }}

     Check all answers on Stack Overflow

     4/5

   • Also try

     how to sort an array in java in ascending order	how to sort an array in java descending
     how to sort an array in java using sort method	how to sort an array in java 8
     how to sort an array in java manually

     5/5

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2. www.geeksforgeeks.org › arrays-sort-in-java-with-examplesArrays.sort() in Java with examples - GeeksforGeeks

   www.geeksforgeeks.org › arrays-sort-in-java-with-examples

   • Cached

   Jul 5, 2024 · To sort the array of objects in both ascending and descending order in Java, we can use the Arrays.sort() method with the Comparator. In this article, we will learn how to sort an array of objects using Arrays.sort(). Sorting an Array of ObjectWith Array of Object what it really means is an array storing any type of object can be Integer, String or

3. www.w3schools.com › java › java_howto_sort_an_arrayJava How To Sort an Array - W3Schools

   www.w3schools.com › java › java_howto_sort_an_array

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   How To Sort an Array. You can use the sort() method, found in java.util.Arrays, to sort an array:

4. www.baeldung.com › java-sorting-arraysSorting Arrays in Java | Baeldung

   www.baeldung.com › java-sorting-arrays

   • Cached

   Jan 8, 2024 · Java’s util.Arrays.sort method provides us with a quick and simple way to sort an array of primitives or objects that implement the Comparable interface in ascending order. When sorting primitives, the Arrays.sort method uses a Dual-Pivot implementation of Quicksort.

5. www.geeksforgeeks.org › sorting-in-javaSorting in Java - GeeksforGeeks

   www.geeksforgeeks.org › sorting-in-java

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   Mar 15, 2024 · In Java, sorting an array consists of arranging the elements in a particular order, such as ascending or descending. This can be achieved using various algorithms like Bubble Sort, Selection Sort, or Insertion Sort. A menu-driven program allows users to select the desired sorting method dynamically. In this article, we will learn to implement a men

6. codegym.cc › groups › postsHow to Sort an Array in Java - CodeGym

   codegym.cc › groups › posts

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   May 11, 2023 · Arrays.sort (Array, fromIndex, toIndex): This overloaded sort method allows you to sort only a portion of the Array specified by the fromIndex and toIndex parameters. Arrays.sort (Array, comparator): this one is for sorting arrays of objects using a custom comparator. The comparator defines the ordering of the elements.

7. howtodoinjava.com › java › sortHow to Sort an Array, List, Map or Stream in Java - HowToDoInJava

   howtodoinjava.com › java › sort

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   Use java.util.Arrays.sort() method to sort a given array in a variety of ways. The sort() is an overloaded method that takes all sorts of types as the method argument. This method implements a Dual-Pivot Quicksort sorting algorithm that offers O(n log(n)) performance on all data sets and is typically faster than traditional (one-pivot ...

8. ioflood.com › blog › sort-array-javaJava Array Sorting: Methods, Tips, and Examples

   ioflood.com › blog › sort-array-java

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   Nov 9, 2023 · Java provides the Arrays.sort() method to sort an array. It’s as simple as calling this method with your array as the argument. Here’s a simple example: int[] arr = {3, 1, 4, 1, 5}; Arrays.sort(arr); System.out.println(Arrays.toString(arr)); // Output: // [1, 1, 3, 4, 5]

9. howtodoinjava.com › java › sortSorting Arrays in Java - HowToDoInJava

   howtodoinjava.com › java › sort

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   Feb 4, 2022 · Learn to sort a Java array of primitives, strings and custom objects in multiple ways with the help of Comparable and Comparator interfaces, Arrays.sort () and Stream.sorted () APIs.

10. www.codejava.net › java-core › collectionsJava Sort Arrays Examples (with Comparable and Comparator)

    www.codejava.net › java-core › collections

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    To sort an array of objects into the reverse of natural ordering of its elements, we can use this syntax: Arrays.sort(array, Collections.reverseOrder()); The Collections.reverseOrder() static method returns a Comparator object that imposes the reverse of natural ordering on a collection of objects that implement the Comparable interface. For ...

11. www.geeksforgeeks.org › sorting-in-arraySorting in Array | How to Sort an Array - GeeksforGeeks

    www.geeksforgeeks.org › sorting-in-array

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    Jul 5, 2024 · Given an array arr[] consisting of N strings, the task is to sort the array in ascending order after modifying each string by removing all characters that are not perfect power of 2 and then sort the modified string in decreasing order.