How to Sort Array in C#: Simple Guide with Examples

In C#, you can sort an array using the Array.Sort() method which sorts the elements in ascending order by default. For custom sorting, you can provide a comparison delegate or use LINQ methods like OrderBy().

Syntax

The basic syntax to sort an array in C# is using the Array.Sort() method. It modifies the original array by sorting its elements in ascending order.

• Array.Sort(array); - Sorts the entire array in ascending order.
• Array.Sort(array, startIndex, length); - Sorts a portion of the array.
• Array.Sort(array, comparer); - Sorts using a custom comparer.

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Array.Sort(array);

Example

This example shows how to sort an integer array in ascending order using Array.Sort(). It prints the array before and after sorting.

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using System;

class Program
{
    static void Main()
    {
        int[] numbers = { 5, 3, 8, 1, 2 };
        Console.WriteLine("Before sorting: " + string.Join(", ", numbers));

        Array.Sort(numbers);

        Console.WriteLine("After sorting: " + string.Join(", ", numbers));
    }
}

Output

Before sorting: 5, 3, 8, 1, 2
After sorting: 1, 2, 3, 5, 8

Common Pitfalls

Some common mistakes when sorting arrays in C# include:

• Expecting Array.Sort() to return a new sorted array. It sorts the original array in place.
• Trying to sort arrays of custom objects without implementing IComparable or providing a comparer.
• Using OrderBy() without converting the result back to an array if you need an array.

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/* Wrong: expecting Array.Sort to return a sorted array */
int[] nums = {3, 1, 2};
// int[] sorted = Array.Sort(nums); // This causes a compile error

/* Right: sort in place */
Array.Sort(nums);

/* Wrong: sorting custom objects without comparer */
// class Person { public string Name; }
// Person[] people = ...;
// Array.Sort(people); // Throws exception

/* Right: provide comparer or implement IComparable */

Quick Reference

Here is a quick summary of sorting arrays in C#:

Method	Description
Array.Sort(array)	Sorts entire array in ascending order in place
Array.Sort(array, startIndex, length)	Sorts a subrange of the array
Array.Sort(array, comparer)	Sorts using a custom comparer
array.OrderBy(x => x).ToArray()	Returns a new sorted array using LINQ

Key Takeaways

Use Array.Sort() to sort arrays in place in ascending order.

Array.Sort() modifies the original array; it does not return a new one.

For custom sorting, provide a comparer or use LINQ's OrderBy.

Remember to convert LINQ results back to array if needed.

Sorting custom objects requires implementing IComparable or a comparer.