Inserting spaces between specific pairs of letter characters?

Questions
1

Hello everyone,

I have many short strings of words that have been joined (no spaces) and where the first character of each word is capitalized (title case), for example, OnTopOfTheWorld. I want to insert spaces in between the words, and the only way I could come up with doing that is by partitioning the strings into characters, identifying the positions of the caps, and inserting a space before each cap. My code looks like this:

str = "OnTopOfTheWorld";
StringTrim[
 StringInsert[str, " ", 
  Flatten[Position[UpperCaseQ /@ StringPartition[str, 1], True]]]]

It works fine, but I thought there might be a more elegant way to do it with StringReplace. Any thoughts?

Greg

2

Here is one way

StringSplit["OnTopOfTheWorld", RegularExpression["(?<=[a-z])(?=[A-Z])"]]
(* {"On", "Top", "Of", "The", "World"} *)

To handle more complex cases, take a look at this SE thread.

3

That certainly works. Thanks!

4

That certainly works. Thanks! And in StringReplace, can be written as

StringReplace["OnTopOfTheWorld", 
 lowerCaseChar : CharacterRange["a", "z"] ~~ 
   upperCaseChar : CharacterRange["A", "Z"] -> 
  lowerCaseChar ~~ " " ~~ upperCaseChar]
5

Another alternative:

StringReplace["OnTopOfTheWorld", RegularExpression["([a-z])([A-Z])"] -> "$1 $2"]
6

Good stuff. Thanks. I’ll have to do my homework on RegEx so that I can switch between Wolfram functions and RegEx.