C# Online Compiler | .NET Fiddle

using System;
					
public class Program
{
	public static void Main()
	{
		 string sBinVal = "11000110";
            
		//Call the function to convert binary to decimal in C#.
		long decVal = BinaryToDecimal(sBinVal);

		if(decVal != -1)
		{
			Console.WriteLine("Binary Number: " + sBinVal);
			Console.WriteLine("Decimal: " + decVal);
		}
		else
		{
			Console.WriteLine("Input is invalid");
		}
	}
	
	/// <summary>
        /// Convert Binary into Decimal using Math function in C#.
        /// </summary>
        /// <param name="binValue">The binary value in string</param>
        /// <returns>The decimal value</returns>
        public static int BinaryToDecimal(string binValue)
        {
            char[] array = binValue.ToCharArray();

            // Reverse since 16-8-4-2-1 not 1-2-4-8-16. 
            Array.Reverse(array);
            /*
             * [0] = 1
             * [1] = 2
             * [2] = 4
             * etc
             */
            int decVal = 0;

            for (int i = 0; i < array.Length; i++)
            {
                if (array[i] == '1')
                {
                    // Method uses raising 2 to the power of the index. 
                    if (i == 0)
                    {
                        decVal += 1;
                    }
                    else
                    {
                        decVal += (int)Math.Pow(2, i);
                    }
                }

            }

            return decVal;
        }
}

 
using System;
                    
public class Program
{
    public static void Main()
    {
         string sBinVal = "11000110";
            
        //Call the function to convert binary to decimal in C#.
        long decVal = BinaryToDecimal(sBinVal);
​
        if(decVal != -1)
        {
            Console.WriteLine("Binary Number: " + sBinVal);
            Console.WriteLine("Decimal: " + decVal);
        }
        else
        {
            Console.WriteLine("Input is invalid");
        }
    }
    
    /// <summary>
        /// Convert Binary into Decimal using Math function in C#.

Hello World