How to remove duplicate number in array

Question

how to remove duplicate number in array

Rohan Mistry · Answer

Hello Haider Ali in c# you can use "Distinct" to remove duplication from the array and if you want to remove duplication and merge array then use "Union". using System; using System.Linq; namespace QueAnsForDuplicateNumber { class Program { static void Main(string[] args) { int [] first = { 15, 25, 36, 87, 52, 25, 36, 52, 36, 87 }; int [] second = { 15, 60, 36, 90, 52, 25, 36, 36, 36, 87 }; int [] removeDuplicate = first.Distinct().ToArray(); //Distinct() Use for remove duplication Console.WriteLine(); Console.WriteLine($ "First Array-> [{ string.Join(" , ", first)}] " ); Console.WriteLine($ "Remove Duplication From First Array-> [{ string.Join(" , ", removeDuplicate)}] " ); Console.WriteLine($ "===========================================================" ); int [] removeDuplicateFromFirstAndSeconf = first.Union(second).ToArray(); //Union() Use for merge array without duplication Console.WriteLine($ "First Array-> [{ string.Join(" , ", first)}] " ); Console.WriteLine($ "Second Array-> [{ string.Join(" , ", second)}] " ); Console.WriteLine($ "Remove Duplication From First and Second Array and Merge Array -> [{ string.Join(" , ", removeDuplicateFromFirstAndSeconf)}] " ); Console.ReadKey(); } } } Output:

Daril · Answer

public static void main(String[] args) { int arg[]; int temp[]; temp=new int[1000]; arg=new int[500]; Scanner S=new Scanner(System.in); int j=S.nextInt(); int k= 0; int l=0; for(int i=0;i { arg[i]=S.nextInt(); } for(int i=0;i { for(l=0;l { if(arg[i]==temp[l]) break; } if(l==k) { temp[k]=arg[i]; k++; } } for(int i=0;i { System.out.println(temp[i]); } }

Farhan Ahmed · Answer

https://www.geeksforgeeks.org/remove-duplicates-sorted-array/

Mahesh Deshmane · Answer

Here is quick solution using Linqvar arr = new [] { 101, 51, 10, 2, 2, 3, 4, 5, 15, 6, 7, 8, 9, 101, 12, 12 };var result = arr.GroupBy(v => v);You can also use Dictionary

Surendra Kandira · Answer

Declare a int type variable int [] newArray= new int[]{1,2,3,1,2,4,4,5,1,3,6,7,6,8,1,5}; Using a function "Distinct() ". This function is already define in c# and you remove duplicate data or value in any type array Using this santax .......... newArray=newArray.Distinct().ToArray(); now newArray only store single value not duplicate value Like .. 1,2,3,4,5,6,7,8

jaya kumar · Answer

That's great Vulpes, i think it's good idea to solve. Thanks Vulpes.

Vulpes · Answer

This is an old thread but it's trivial nowadays to remove duplicates using LINQ: using System; using System.Linq; class Program { static void Main(string[] args) { int[] ia = {1,2,3,1,2,4,4,5,1,3,6,7,6,8,1,5}; int[] ia2 = ia.Distinct().ToArray(); foreach(int i in ia2) Console.Write("{0} ", i); Console.WriteLine(); Console.ReadKey(); } }

jaya kumar · Answer

Hai All, To remove duplication an integer array. Main Class using System; using System.Collections; class Program { static void Main(string[] args) { Console.WriteLine("Main Program Started..."); int[] duplicateValues = new int[]{1,2,3,1,2,4,4,5,1,3,6,7,6,8,1,5}; DublicationRemove Obj = new DublicationRemove (); int[] resultValues = Obj.removeDuplicationValues(duplicateValues); for (int i = 0; i { Console.Write(resultValues[i]); } } } My Duplication Class using System; using System.Collection; using System.Text; using System.Linq; using System.Collections.Generic; public class DublicationRemove { public DublicationRemove() { //Constructor.... } public int[] removeDuplicationValues(int[] values) { ArrayList result = new ArrayList(); foreach (int s in values) { if (!result.Contains(s)) { result.Add(s); } } return (int[])result.ToArray(typeof(int)); } } I hope this would help you.

Jignesh Kumar · Answer

Hi Haider Ali, Please use this generic method for remove duplicate, using System; using System.Collections.Generic; public class Example { public static T[] removeDuplicates (T[] array) { HashSet set = new HashSet (array); T[] result = new T[ set .Count]; set .CopyTo(result); return result; } public static void Main() { int [] array = { 1, 2, 2, 3, 4, 4, 5, 6, 6, 6, 7, 7 }; int [] distinct = removeDuplicates(array); Console.WriteLine(String.Join( "," , distinct)); } } Output : 1,2,3,4,5,6,7

sunil yadav · Answer

this program did not remove duplicate number... this is worng programming

haider ali · Answer

Thanks Allan

haider ali · Answer

Thanks mahvish for your reply hoping for more replying my question

Alan · Answer

Here's a version for C# which removes all duplicates from an 'int' array: using System; using System.Collections; class Program { static void Main() { int[] ia = new int[]{1,2,3,1,2,4,4,5,1,3,6,7,6,8,1,5}; int[] ia2 = RemoveDuplicates(ia); foreach(int i in ia2) { Console.Write("{0} ", i); } Console.WriteLine(); Console.ReadLine(); } static int[] RemoveDuplicates(int[] ia) { if (ia == null || ia.Length == 1) return ia; ArrayList al = new ArrayList(ia); al.Sort(); for(int i = al.Count - 1; i > 0; i--) { if ((int)al[i] == (int)al[i-1]) al.RemoveAt(i); } return (int[])al.ToArray(typeof(int)); } }

Manish Dwivedi · Answer

Hi, U can remove the duplicate number by the following code. ' Filter out duplicate values in an array and compact ' the array by moving items to "fill the gaps". ' Returns the number of duplicate values ' ' The array is not REDIMed, but you can do it easily using ' the following code: ' a() is a string array ' dups = FilterDuplicates(a()) ' If dups Then ' ReDim Preserve a(LBound(a) To UBound(a) - dups) As String ' End If Function FilterDuplicates(ByVal arr As Array) As Integer Dim index As Integer Dim dups As Integer ' we use a hashtable to track duplicates Dim ht As New Collections.Hashtable(arr.Length * 2) For index = 0 To arr.Length - 1 Dim value As Object = arr.GetValue(index) If ht.Contains(value) Then ' we've found a duplicate arr.SetValue(Nothing, index) dups += 1 Else ' add to the hashtable (use a dummy Nothing value) ht.Add(value, Nothing) ' if we've found one or more duplicates so far ' we need to move elements towards lower indices If dups > 0 Then arr.SetValue(value, index - dups) arr.SetValue(Nothing, index) End If End If Next ' return the number of duplicates Return dups End Function

How to remove duplicate number in array

Answers (14)