What is the best way of converting a number to a alphabet string?

Question

What is the best way of converting a multi-digit number to a alphabet string in C#.

For example, if I have a number say,

int digits = 1234567890

I want this to be converted to a string which would be

string alpha = "ABCDEFGHIJ"

This means 1 represents A, 2 represents B and so on.

Answer 1

Make an array of chars:

char alphabet = {'A','B','C' .... }

Then use the digit number as the index of the array:

digit = 14567
char[] digit_ar = new String(digit).ToCharArray();

foreach (char c in digit_ar)
{
    string s+=digit_ar[Convert.ToInt32(c)-Base];
}

Base is the A char code

This is a pseudo code and I've not tested it!

It should works...

Answer 2

Use Dictionary class, look at this.

Answer 3

Something like this:

int input = 123450;
string output = "";

while (input > 0)
{
    int current = input % 10;
    input /= 10;

    if (current == 0)
        current = 10;

    output = (char)((char)'A' + (current - 1)) + output;
}

Console.WriteLine(output);

The above saves you the trouble of having to define a conversion list through an array or dictionary. The conversion can be done simply calculating the correct Unicode codepoint.

Answer 4

There are not too many different symbols to replace, just a simple replace would be easy.

int digits = 0123456789;
string digitsAsString = digits.ToString("0000000000"); // Trick to preserve the 0.
string alpha = digitsAsString
    .Replace('0', 'A')
    .Replace('1', 'B')
    .Replace('2', 'C')
    .Replace('3', 'D')
    .Replace('4', 'E')
    .Replace('5', 'F')
    .Replace('6', 'G')
    .Replace('7', 'H')
    .Replace('8', 'I')
    .Replace('9', 'J');
Console.WriteLine(alpha);

Answer 5

First of all, 0123 would be interpreted as 123, so the leading 0 would be ignored. Here's one possible solution:

int i = 1230468;
StringBuilder res = new StringBuilder(i.ToString());

for (int j = 0; j < res.Length; j++)
   res[j] += (char)(17); // '0' is 48, 'A' is 65

Console.Out.WriteLine(res.ToString()); // result is BCDAEGI

Answer 6

Pay attention to this instruction

"output = (char)((char)'A' + (current - 1)) + output;"

At every iteration it creates new objects. String concatenation must be done with StringBuilder...

I have to do a general consideration to the answers given to this post. A developer must pay attention not only to the elegance, or algorithm efficiency but to memory efficiency too.

C# is not C o C++ and Objects are bad animals :-)