Binary Search in C#

using System;

public static class BinarySearch 
{

// Assumes 'arr' is in sorted order.

// Iterative implementation of Binary Search
public static int BinarySearchIterative(int[] arr, int num) 
   {
    int mid, low, high;
    low = 0;
    high = arr.Length - 1;
    
    while(low <= high) 
       {
        
        mid = (low + high) / 2;
        
        if(num < arr[mid]) 
           {
            high = mid - 1;
        }
        else if(num > arr[mid]) 
           {
            low = mid + 1;
        }
        else  
           {
            return mid;
        }
    }
    return -1;
}

// Recursive implementation of Binary Search
public static int BinarySearchRecursive(int[] arr, int num) 
   {
    return BinarySearchRecursiveAux(arr, num, 0, arr.Length  - 1);
}
// Helper method for the recursive approach.
private static int BinarySearchRecursiveAux(int[] arr, int num, int low, int high) 
   {
    int mid =  (low + high) / 2;
    
    if(low >= high) return -1;

       if (num < arr[mid])
       {
           return BinarySearchRecursiveAux(arr, num, low, mid - 1);
       }
       else if (num > arr[mid])
       {
           return BinarySearchRecursiveAux(arr, num, mid + 1, high);
       }
       else
       {
           return mid;
       }
   }
}