# How to Combine Two Arrays without Duplicate values in C#?

• Last Updated : 01 Nov, 2021

Given two arrays, now our task is to merge or combine these arrays into a single array without duplicate values. So we can do this task using the Union() method. This method combines two arrays by removing duplicated elements in both arrays. If two same elements are there in an array, then it will take the element only once.

Syntax:

first_array.Union(second_array)

Examples:

```Input  : array1 = {22, 33, 21, 34, 56, 32}
array2 = {24, 56, 78, 34, 22}
Output : New array = {22, 33, 21, 34, 56, 32, 24, 78}

Input  : array1 = {1}
array2 = {2}
Output : New array = {1, 2}```

## Approach

1. Declare two arrays of any type integer, string, etc.

2. Apply Union() function and convert to array using ToArray() function.

`final = array1.Union(array2).ToArray();`

3. Now iterate the elements in the final array using ForEach() function.

`Array.ForEach(final, i => Console.WriteLine(i));`

4. We can also iterate the array using IEnumerable method.

```IEnumerable<int> final = array1.Union(array2);
foreach (var in final)
{
Console.WriteLine(i);
} ```

Example 1:

## C#

 `// C# program to merge two array into a single``// array without duplicate elements``using` `System;``using` `System.Collections.Generic;``using` `System.Linq;`` ` `class` `GFG{`` ` `public` `static` `void` `Main()``{``     ` `    ``// Declare first array with integer numbers``    ``int``[] array1 = { 22, 33, 21, 34, 56, 32 };``     ` `    ``// Declare second array with integer numbers``    ``int``[] array2 = { 24, 33, 21, 34, 22 };``     ` `    ``// Displaying array 1``    ``Console.WriteLine(``"Array 1: "``);``     ` `    ``foreach` `(``int` `x1 ``in` `array1)``    ``{``        ``Console.WriteLine(x1);``    ``}``     ` `    ``// Displaying array 2``    ``Console.WriteLine(``"Array 2: "``);``     ` `    ``foreach` `(``int` `x2 ``in` `array2)``    ``{``        ``Console.WriteLine(x2);``    ``}``     ` `    ``// Combine the unique elements and convert into array``    ``var` `final = array1.Union(array2).ToArray();``     ` `    ``// Display the elements in the final array``    ``Console.WriteLine(``"New array:"``);``    ``Array.ForEach(final, i => Console.WriteLine(i));``}``}`

Output:

```Array 1:
22
33
21
34
56
32
Array 2:
24
33
21
34
22
New array:
22
33
21
34
56
32
24```

Example 2:

## C#

 `// C# program to merge two array into a single``// array without duplicate elements``using` `System;``using` `System.Collections.Generic;``using` `System.Linq;``                     ` `class` `GFG{`` ` `public` `static` `void` `Main()``{``     ` `    ``// Declare first array with strings ``    ``string``[] array1 = { ``"ojaswi"``, ``"gnanesh"``, ``"bobby"` `};    ``     ` `    ``// Declare second array with also strings``    ``string``[] array2 = { ``"rohith"``, ``"ojaswi"``, ``"bobby"` `};``     ` `    ``// Displaying array 1``    ``Console.WriteLine(``"Array 1: "``);``     ` `    ``foreach` `(``string` `x1 ``in` `array1)``    ``{``        ``Console.WriteLine(x1);``    ``}``     ` `    ``// Displaying array 2``    ``Console.WriteLine(``"\nArray 2: "``);``     ` `    ``foreach` `(``string` `x2 ``in` `array2)``    ``{``        ``Console.WriteLine(x2);``    ``}``     ` `    ``// Combine the unique elements and convert into array``    ``IEnumerable<``string``> final1 = array1.Union(array2); ``     ` `    ``Console.WriteLine(``"\nNew array:"``);``     ` `    ``// Display the elements in the final array``    ``foreach` `(``var` `j ``in` `final1)    ``    ``{    ``        ``Console.WriteLine(j);    ``    ``} ``}``}`

Output:

```Array 1:
ojaswi
gnanesh
bobby

Array 2:
rohith
ojaswi
bobby

New array:
ojaswi
gnanesh
bobby
rohith```

My Personal Notes arrow_drop_up