Find the maximum number in an array in C# without using any built-in methods

To find the maximum number in an array in C# without using any built-in methods, you can iterate through the array and keep track of the maximum number encountered. Here's how you can do it:

using System;

class Program
{
    static void Main(string[] args)
    {
        // Sample array
        int[] numbers = { 10, 5, 8, 20, 3, 15 };

        // Variable to store the maximum number
        int max = numbers[0]; // Initialize max with the first element of the array

        // Iterate through the array starting from the second element
        for (int i = 1; i < numbers.Length; i++)
        {
            // Check if the current element is greater than the current max
            if (numbers[i] > max)
            {
                // Update max if the current element is greater
                max = numbers[i];
            }
        }

        // Print the maximum number
        Console.WriteLine("The maximum number in the array is: " + max);
    }
}

In the above code:

• We initialize max with the first element of the array.
• We iterate through the array starting from the second element.
• In each iteration, we compare the current element with the current maximum (max).
• If the current element is greater than the current maximum, we update max with the value of the current element.
• Finally, we print out the maximum number after the loop has finished iterating through the array.