Question

I am trying to input a string into a C# console app, have it break the string into an array of its characters, and then have it iterate through the array of characters and assign each character an integer corresponding to its alphabetic position(1-26, a-z) and populate a new array with the integers.

The input block up to the array of characters I already have:

string plainText;
Console.Write ("String:");
plainText = Console.ReadLine();
char[] plainTextArray = plainText.ToCharArray();

Not looking for a completed solution, more of a suggested direction to look in for a function(s) to implement.

Thanks.

Answer 1

Two possible solutions here:

• Convert the char to an int, subtract an appropriate amount to put it between 1-52, and take the number mod 26 (or .ToUpper() or ToLower() the string beforehand and put it in the 1-26 range)
• Create and prepopulate a mapping (something like Dictionary<char, int> that takes a char and returns the appropriate number

I recommend the first option.

EDIT:
Based on phoog’s comment, I recommend the following method:

1. Use String.ToUpper() to convert the string to uppercase.
2. Use String.ToCharArray() to create the array of uppercase characters.
3. Create an int[] array that is the same size as the char[] array.
4. Iterate through the length of the arrays, converting char to int using `(plainTextArray[i] – ‘a’) + 1