How to split a character without removing it (regex)

Question

I want to split a string at a certain point, but keep the character I'm splitting it at. For example:

Input:
a:b

Output:
a
:
b

Is there anyway I can use this with Java's split() method? Thanks :)

Answer 1

You can use StringTokenizer class in Java.

StringTokenizer stk = new StringTokenizer(inputStr,":", true);

This will return tokens as well as delimiter.

Answer 2

Quick solution from my mind

1. First split it from the character you want to split
2. Join it with another string like this ____:____
3. Now, split again with ____

____ is just a string which I am sure doesn't exist in the string. You can use anyother substring as well depending upon your use case

Order of time complexity O(3*N)

For Example

Your string is a:b.

1. Split it with :

   String Array you get is ["a", "b"]

2. Join with ____:____

   String you get is a_:_b

3. Split again with ____

   You get ["a", ":", "b"] (desired output)

Just giving an idea.

Answer 3

Scanner  = new Scanner(System.in);
String input = s.next();
for (String str : input.split()) {
  System.out.println(str);
  System.out.println(":");
}