Program to convert a binary number to hexadecimal number

// C# implementation to convert a
// binary number to hexadecimal number

using System;
using System.Collections.Generic;

public class GFG {

    // Function to create map between binary
    // number and its equivalent hexadecimal
    static IDictionary<string, char>
    createMap(IDictionary<string, char> um)
    {
        um.Add("0000", '0');
        um.Add("0001", '1');
        um.Add("0010", '2');
        um.Add("0011", '3');
        um.Add("0100", '4');
        um.Add("0101", '5');
        um.Add("0110", '6');
        um.Add("0111", '7');
        um.Add("1000", '8');
        um.Add("1001", '9');
        um.Add("1010", 'A');
        um.Add("1011", 'B');
        um.Add("1100", 'C');
        um.Add("1101", 'D');
        um.Add("1110", 'E');
        um.Add("1111", 'F');
        return um;
    }

    // Function to find hexadecimal
    // equivalent of binary
    static String convertBinToHex(String bin)
    {
        int i;
        int l = bin.Length;
        int t = bin.IndexOf('.');

        // Length of string before '.'
        int len_left = t != -1 ? t : l;

        // Add min 0's in the beginning to make
        // left substring length divisible by 4
        for (i = 1; i <= (4 - len_left % 4) % 4; i++)
            bin = '0' + bin;

        // If decimal point exists
        if (t != -1) {

            // Length of string after '.'
            int len_right = l - len_left - 1;

            // Add min 0's in the end to make right
            // substring length divisible by 4
            for (i = 1; i <= (4 - len_right % 4) % 4; i++)
                bin = bin + '0';
        }

        // Create map between binary and its
        // equivalent hex code
        IDictionary<string, char> bin_hex_map
            = new Dictionary<string, char>();

        bin_hex_map = createMap(bin_hex_map);

        i = 0;
        string hex = "";

        while (true) {

            // One by one extract from left, substring
            // of size 4 and add its hex code

            hex += bin_hex_map[bin.Substring(i, 4)];
            i += 4;

            if (i == bin.Length)
                break;

            // If '.' is encountered add it
            // to result
            if (bin[i] == '.') {
                hex += '.';
                i++;
            }
        }

        // Required hexadecimal number
        return hex;
    }
    public static void Main(string[] args)
    {
        string bin = "1111001010010100001.010110110011011";

        Console.WriteLine("Hexadecimal number = "
                          + convertBinToHex(bin));
    }
}

// This code is contributed by phasing17.

using System;

class Program {
    static string bin_to_hex(string binary) {
        binary = binary.PadLeft((binary.Length / 4 + 1) * 4, '0');
        string[] hex_dict = {"0", "1", "2", "3", "4", "5", "6", "7",
                             "8", "9", "A", "B", "C", "D", "E", "F"};
        string hexadecimal = "";
        for (int i = 0; i < binary.Length; i += 4) {
            string group = binary.Substring(i, 4);
            int index = Convert.ToInt32(group, 2);
            hexadecimal += hex_dict[index];
        }
        return hexadecimal;
    }

    static void Main(string[] args) {
        string binary = "110001110";
        string hexadecimal = bin_to_hex(binary);
        Console.WriteLine(hexadecimal);
    }
}