Why isn't my C# Selection Sort algorithm outputting the expected result?

Question

So I'm trying to implement selection sort in C# but the output isn't exactly what I'm expecting, I tried tracing the loops and even brought out the good ol pen and paper but to no avail

using System;
namespace App
{
    class Application
    {
        public static void Main(string[] args)
        {
            int[] arr = {23,45,76,22,5666,845,11,2};
            foreach (int i in sort(arr))
            {
                Console.WriteLine($"{i}");
                
            }
        }
        public static int[] sort(int[] arr)
        {
            int ind = 0;
            int minInd = 0;
            int jInd = 0;
            foreach(int i in arr)
            { 
                int min = i;
                minInd = ind;
                foreach(int j in arr)
                {
                    if (i == j)
                    {

                    }
                    else
                    {
                        if (j < min)
                        {
                            min = j;
                            minInd = jInd;
                        }                        
                    }
                    jInd++;
                }
                int temp = i;
                arr[ind] = arr[minInd];
                arr[minInd] = temp;
                ind++;
                jInd = 0;
            }
            return arr;
        }
    }

}

for some info, minInd is the index of the minimum value, ind is the index of the outer loop iteraion, and jInd is the index for the inner loop itteration, i tried using the built in IndexOf from the array class but that just results in an indexoutofbounds error, could be a problem in the way C# handles array, i normally use java so maybe they handle them in different ways, also I understand that the time complexity of this algorithm is n^2 so why do we still use it.

The output is 45 76 22 5666 845 11 23 2

Answer 1

You do not need to make your method return a sorted integer array as the integer array you passed as a parameter is sorted by moving elements to different array indices after comparing consecutive elements using the selection sort algorithm. To implement a method that sorts an integer array in ascending order using the Selection Sort algorithm then the code below would work for you.

 static void SelectionSorter(int[] arr)
        {
            for(int i=0;i< arr.Length; i++)
            {
                for(int j=i+1;j<arr.Length;j++)
                {
                    if (arr[i] >= arr[j])
                    {
                        //swap the elements so smaller elements come first
                        int temp = arr[i];
                        arr[i] = arr[j];
                        arr[j] = temp;
                    }
                }
            }

Use the method to sort the elements of your array inside the Main method by calling the method above and passing your integer array as a parameter.

static void Main(string[] args){
int[] arr = {23,45,76,22,5666,845,11,2};
SelectionSorter(arr);
//print out the elements to the console
arr.ToList().ForEach(item=>Console.Write(item+" "));
//outputs 2 11 22 23 45 76 845 5666
}