How to sort an Array in C# | Array.Sort() Method Set – 2

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, Int32, Int32, IComparer) Method
• Sort(Array, Array, Int32, Int32, IComparer) Method
• Sort(Array, Int32, Int32) Method
• Sort(Array, Array, Int32, Int32) Method

Sort(Array, Int32, Int32, IComparer) Method

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

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

Parameters:

“arr” :It is the one-dimensional array to sort.
“start” : It is the starting index of the range to sort.
“len” : It is the number of elements in the range to sort.
“comparer” : It is the IComparer implementation to use when comparing elements or null to use the IComparable implementation of each element.

Exceptions:

• ArgumentNullException: If the array is null.
• RankException: If the array is multidimensional.
• ArgumentOutOfRangeException if the start index is less than the lower bound of array or len is less than zero.
• ArgumentException: If the start index and len does not specify a valid range in array or if the implementation of comparer caused an error during the sort.
• InvalidOperationException: If comparer is null, and one or more elements in array do not implement the IComparable interface.

Example:

// C# program to demonstrate the use
// of  Array.Sort(Array, Int32, Int32,
// 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 a array.
        string[] arr = {"ABC", "GHI", "JKL",
                       "DEF", "MNO", "XYZ"};

        // Instantiate the reverse comparer.
        IComparer g = new comparer();

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

        // Sort a section of the array
        // using the IComparer object
        // sorting happens in the range
        // of index 1 to 4
        // "g" is IComparer object
        Array.Sort(arr, 1, 4, g);

        Console.WriteLine("\nAfter sorting in a range of"+
             " index 1 to 4 using the IComparer object:");

        Display(arr);
    }

    // Display function
    public static void Display(string[] arr)
    {
        for (int i = arr.GetLowerBound(0);
        i <= arr.GetUpperBound(0); i++) {

            Console.WriteLine(arr[i]);
        }
    }
}

Output:

The original order of elements in the array:
ABC
GHI
JKL
DEF
MNO
XYZ

After sorting in a range of index 1 to 4 using the IComparer object:
ABC
DEF
GHI
JKL
MNO
XYZ

Sort(Array, Array, Int32, Int32, IComparer) Method

This method sorts a range of elements in a pair of one-dimensional array objects based on the keys in the first Array using the specified IComparer. Here the objects contain the keys and the corresponding items.

Syntax: public static void Sort (Array key, Array items, int start, int len, IComparer comparer);

Parameters:

key: It is the one-dimensional array which contains the keys to sort.
items: It is the one-dimensional array which contains the items that correspond to each of the keys in the keysArray(previous array).
start: It is the starting index of the range to sort.
len: It is the number of elements in the range to sort.
comparer: It is the IComparer implementation to use when comparing elements or null to use the IComparable implementation of each element.

Exceptions:

• ArgumentNullException: If the key is null.
• RankException: If the keysArray is multidimensional.
• ArgumentOutOfRangeException: If the start index is less than the lower bound of keys or len is less than zero.
• ArgumentException:
  • If the items is not null, and the lower bound of keys does not match the lower bound of items or
  • If the items is not null, and the len of keys is greater than the length of items
  • If the start index and len do not specify a valid range in the keysArray.
  • If the items is not null, and start index and len do not specify a valid range in the itemsArray.
  • If the implementation of comparer caused an error during the sort.
• InvalidOperationException: If the comparer is null.

Example:

// C# program to demonstrate the use
// of Array.Sort(Array, Array, Int32,
// Int32, IComparer) Method
using System;
using System.Collections;

class comparer : IComparer {

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

// Driver Class
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 reverse comparer.
        IComparer g = new comparer();

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

        Display(arr1, arr2);

        // Sort a section of the array
        // using the IComparer object
        // sorting happens in the range
        // of index 1 to 4
        // "g" is IComparer object
        Array.Sort(arr1, arr2, 1, 4, g);

        Console.WriteLine("\nAfter sorting in a "+
                       "range of index 1 to 4 :");

        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 in a range of index 1 to 4 :
H : A
L : C
K : D
J : E
I : F
N : B
M : G

Sort(Array, Int32, Int32) Method

This method sorts the elements in a range in a one-dimensional array using the IComparable implementation of each element of the Array.

Syntax: public static void Sort (Array arr, int start, int len);

Parameters:

arr: It is the one-dimensional array to sort.
start: It is the starting index of the range to sort.
len: It is the number of elements in the range to sort.

Exceptions:

• ArgumentNullException: If the array is null.
• RankException: If the array is multidimensional.
• ArgumentOutOfRangeException: If the start index is less than the lower bound of array or len is less than zero.
• ArgumentException: If the start index and len does not specify a valid range in array.
• InvalidOperationException: If the one or more elements in array do not implement the IComparable interface.

Example:

// C# program to demonstrate the use of
// Array.Sort(Array, Int32, Int32) method
using System;
using System.Collections;

class GFG {

    // Main Method
    public static void Main()
    {
        // initialize a array.
        string[] arr = {"ABC", "GHI", "JKL",
                       "DEF", "MNO", "XYZ"};

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

        Display(arr);

        // sorting happens in the
        // range of index 1 to 4
        Array.Sort(arr, 1, 4);

        Console.WriteLine("\nAfter sorting in a range of "+
               "index 1 to 4 using the IComparer object:");

        Display(arr);
    }

    // Display function
    public static void Display(string[] arr)
    {
        for (int i = arr.GetLowerBound(0);
        i <= arr.GetUpperBound(0); i++) {

            Console.WriteLine(arr[i]);
        }
    }
}

Output:

The original order of elements in the array:
ABC
GHI
JKL
DEF
MNO
XYZ

After sorting in a range of index 1 to 4 using the IComparer object:
ABC
DEF
GHI
JKL
MNO
XYZ

Sort(Array, Array, Int32, Int32) Method

This method sorts a range of elements in a pair of one-dimensional Array objects based on the keys in the first Array using the specified IComparer. Here the objects contain the keys and the corresponding items.

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

Parameters:

key: It is the one-dimensional array which contains the keys to sort.
items: It is the one-dimensional array which contains the items that correspond to each of the keys in the keysArray(previous array).
start: It is the starting index of the range to sort.
len: It is the number of elements in the range to sort.

Exceptions:

• ArgumentNullException: If the key is null.
• RankException: If the keysArray is multidimensional or the itemsArray is multidimensional.
• ArgumentOutOfRangeException: If the start index is less than the lower bound of keys or len is less than zero.
• ArgumentException:
  • If the items is not null, and the len of keys is greater than the length of items.
  • If the start index and len do not specify a valid range in the keysArray.
• If the items is not null, and start index and len do not specify a valid range in the itemsArray.
• If the implementation of comparer caused an error during the sort.

InvalidOperationException: If one or more elements in the keysArray do not implement the IComparable interface.

Example:

// C# program to demonstrate the use of
// Array.Sort(Array, Int32, Int32,
// IComparer) method
using System;
using System.Collections;

class comparer : IComparer {

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

// Driver Class
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"};

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

        // sorting happens in the range of index 1 to 4
        Array.Sort(arr1, arr2, 1, 4);

        Console.WriteLine("\nAfter sorting in a "+
                       "range of index 1 to 4 :");

        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 in a range of index 1 to 4 :
H : A
I : F
J : E
K : D
L : C
N : B
M : G

Reference:

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