Regular expression, split string by capital letter but ignore TLA

Question

I\'m using the regex

System.Text.RegularExpressions.Regex.Replace(stringToSplit, \"([A-Z])\", \" $1\").Trim()

to split strings by capital l

Answer 1

Tomalak's expression worked for me, but not with the built-in Replace function. Regex.Replace(), however, did work.

For i As Integer = 0 To names.Length - 1
  'Worked
  names(i) = Regex.Replace(names(i), "((?<=[a-z])[A-Z]|[A-Z](?=[a-z]))", " $1").TrimStart()

  ' Didn't work
  'names(i) = Replace(names(i), "([A-Z])(?=[a-z])|(?<=[a-z])([A-Z])", " $1").TrimStart()
Next

BTW, I'm using this to split the words in enumeration names for display in the UI and it works beautifully.