Add one space after every two characters and add a character infront of every single character

Question

I want to add one space after every two characters, and add a character in front of every single character.

This is my code:

string str2;
str2 = str1         


        

Answer 1

Try something like this:

static string ProcessString(string input)
{
    StringBuilder buffer = new StringBuilder(input.Length*3/2);
    for (int i=0; i<input.Length; i++)
    {
        if ((i>0) & (i%2==0))
            buffer.Append(" ");
        buffer.Append(input[i]);
    }
    return buffer.ToString();
}

Naturally you'd need to add in some logic about the extra numbers, but the basic idea should be clear from the above.

Answer 2

I think this is what you asked for

string str1 = "3322356";
            string str2;

            str2 = String.Join(" ", 
                str1.ToCharArray().Aggregate("",
                (result, c) => result += ((!string.IsNullOrEmpty(result) &&
                    (result.Length + 1) % 3 == 0) ? " " : "") + c.ToString())
                    .Split(' ').ToList().Select(
                x => x.Length == 1 
                    ? String.Format("{0}{1}", Int32.Parse(x) - 1, x) 
                    : x).ToArray());

result is "33 22 35 56"

Answer 3

[TestMethod]
public void StackOverflowQuestion()
{
    var input = "0123457";
    var temp = Regex.Replace(input, @"(.{2})", "$1 ");
    Assert.AreEqual("01 23 45 7", temp);
}

Answer 4

May be you can try, if i right understand your request,

String.Length % 2

if result is 0, you done with first iteration, if not, just add a character infront of last one.