How to sort an Array in C# | Array.Sort() Method Set – 3

Array.Sort Method is used to sort elements in a one-dimensional array. There are 17 methods in the overload list of this method. Here we will discuss the following methods:

• Sort(Array, IComparer) Method
• Sort(Array, Array, IComparer) Method
• Sort(Array, Array) Method

Sort(Array, IComparer) Method

This method sorts the elements in a one-dimensional array using a specified IComparer.

Syntax: public static void Sort (Array arr, IComparer comparer);

Parameters:
arr: It is the one-dimensional array to sort.
comparer: It is the implementation to use when comparing elements.

Exceptions:

• ArgumentNullException: If the array arr is null.
• RankException: If the array arr is multidimensional.
• InvalidOperationException: If the comparer is null.
• ArgumentException: If the implementation of comparer caused an error during the sort.

Example 1:

// C# program to demonstrate the
// Array.Sort(Array, IComparer) method
using System;
using System.Collections;

class compare : IComparer {

    // Call CaseInsensitiveComparer.Compare
    public int Compare(Object x, Object y)
    {
        return (new CaseInsensitiveComparer()).Compare(x, y);
    }
}

class GFG {

    // Main Method
    public static void Main()
    {

        // Initializing array.
        String[] arr = {"A", "D", "B",
                  "E", "C", "F", "G"};

        // Instantiate the IComparer object
        IComparer cmp = new compare();

        // Display the original values of the array
        Console.WriteLine("The Original array:");
        display(arr);

        // Sort the entire array by using
        // the IComparer object
        // "cmp" is the IComparer object
        Array.Sort(arr, cmp);

        Console.WriteLine("\nAfter sorting the array"+
                             " using the IComparer:");
        display(arr);
    }

    // display function
    public static void display(String[] arr)
    {
        foreach(String a in arr)
            Console.WriteLine(a);
    }
}

Output:

The Original array:
A
D
B
E
C
F
G

After sorting the array using the IComparer:
A
B
C
D
E
F
G

Example 2:

// C# program to demonstrate the
// Array.Sort(Array, IComparer) method
using System;
using System.Collections;

class compare : IComparer {

    // Call CaseInsensitiveComparer.Compare
    public int Compare(Object x, Object y)
    {
        return (new CaseInsensitiveComparer()).Compare(x, y);
    }
}

class GFG {

    // Main Method
    public static void Main()
    {
        // Initializing array.
        int[] arr = {10, 1, 9, 8, 3,
                     4, 6, 5, 2, 7};

        // Instantiate the IComparer object
        IComparer cmp = new compare();

        // Display the original values of the array
        Console.WriteLine("The Original array:");
        display(arr);

        // Sort the entire array by
        // using the IComparer object
        // "cmp" is the IComparer object
        Array.Sort(arr, cmp);

        Console.WriteLine("\n\nAfter sorting the "+
                     "array using the IComparer:");

        display(arr);
    }

    // display function
    public static void display(int[] arr)
    {
        foreach(int a in arr)
            Console.Write(a + " ");
    }
}

Output:

The Original array:
10 1 9 8 3 4 6 5 2 7 

After sorting the array using the IComparer:
1 2 3 4 5 6 7 8 9 10

Sort(Array, Array, IComparer) Method

This method sorts a pair of one-dimensional array objects based on the keys in the first array using the specified IComparer.

Syntax: public static void Sort (Array keys, Array items, IComparer comparer);

Parameters:
keys: It is the one-dimensional array that contains the keys to sort.
items: It is the one-dimensional array that contains the items that correspond to each of the keys in the keys array.
comparer: It is the IComparer implementation to use when comparing elements.

Exceptions:

• ArgumentNullException: If the keys is null.
• RankException: If the keys array is multidimensional or the items array is multidimensional.
• ArgumentException: If the items is not null and the length of keys is greater than the length of items or the implementation of comparer caused an error during the sort.
• InvalidOperationException: If the comparer is null.

Example:

// C# program to demonstrate the
// Array.Sort(Array, Array,
// IComparer) method
using System;
using System.Collections;

class comparer : IComparer {

    // Call CaseInsensitiveComparer.Compare
    public int Compare(Object x, Object y)
    {
        return (new CaseInsensitiveComparer()).Compare(x, y);
    }
}

class GFG {

    // Main Method
    public static void Main()
    {
        // initialize two arrays
        String[] arr1 = {"H", "J", "K",
                   "L", "I", "N", "M"};

        String[] arr2 = {"A", "E", "D",
                   "C", "F", "B", "G"};

        // Instantiate the IComparer object
        IComparer g = new comparer();

        // Display original values of the array.
        Console.WriteLine("The original order of "+
                         "elements in the array:");

        Display(arr1, arr2);

        // Sort the array using IComparer
        // object. "g" is IComparer object
        Array.Sort(arr1, arr2, g);


        Console.WriteLine("\nAfter sorting :");
        Display(arr1, arr2);
    }

    // Display function
    public static void Display(String[] arr1, String[] arr2)
    {
        for (int i = 0; i < arr1.Length; i++) {
            Console.WriteLine(arr1[i] + " : " + arr2[i]);
        }
    }
}

Output:

The original order of elements in the array:
H : A
J : E
K : D
L : C
I : F
N : B
M : G

After sorting :
H : A
I : F
J : E
K : D
L : C
M : G
N : B

Sort(Array, Array) Method

This method sorts a pair of one-dimensional array objects based on the keys in the first Array using the IComparable implementation of each key. Here, in the objects there are two array in which one contains the keys and the other contains the corresponding items.

Syntax: public static void Sort (Array keys, Array items);

Parameters:
keys: It is the one-dimensional array that contains the keys to sort.
items: It is the one-dimensional array that contains the items that correspond to each of the keys in the keys array.

Exceptions:

• ArgumentNullException: If the keys is null.
• RankException: If the keys array is multidimensional or the items array is multidimensional.
• ArgumentException: If the items is not null and the length of keys is greater than the length of items.
• InvalidOperationException: If the one or more elements in the keys array do not implement the IComparable interface.

Example:

// C# program to demonstrate the
// Array.Sort(Array, Array) method
using System;

class GFG {

    // Main Method
    public static void Main()
    {
        // initialize two array.
        int[] arr1 = {7, 5, 2, 3, 1, 6, 4};
        string[] arr2 = {"A", "E", "D",
                   "C", "F", "B", "G"};

        // Display original values of the array.
        Console.WriteLine("The original array:");
        Display(arr1, arr2);

        // Sort the array using two array
        // "arr1" is keys array
        // "arr2" item array
        Array.Sort(arr1, arr2);

        Console.WriteLine("\nAfter Sorting :");
        Display(arr1, arr2);
    }

    // Display function
    public static void Display(int[] arr1, string[] arr2)
    {
        for (int i = 0; i < arr1.Length; i++)
        {
            Console.WriteLine(arr1[i] + " : " + arr2[i]);
        }
    }
}

Output:

The original array:
7 : A
5 : E
2 : D
3 : C
1 : F
6 : B
4 : G

After Sorting :
1 : F
2 : D
3 : C
4 : G
5 : E
6 : B
7 : A

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.array.sort?view=netframework-4.7.2