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

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