Question

I have a very large String. It can be seen here:
http://pastebin.com/vqXJ3WV6

I want to split this string using the regex 3.8
When I search this string using notepad, I find two instances of 3.8.
Therefore, I would expect the array which is returned to have a length of 3.

System.err.println(convertPdfToText(save).split("3.8").length);

However, calling this with convertPdfToText fetching this String has a length of 4?

I do not understand this at all in the slightest. Can anybody tell me what is going on because this is changing the behaviour of my program massively.

Thanks in advance

Answer 1

The . character is a special character in regex which literally means “any character”. So you’re basically looking for 3[anything]8, and a quick regex search shows that there is indeed 3 matches for that. Two are the valid “3.8” strings you were actually looking for. Your unintended match is located at the end of this string:

3.4 Unit 3: Spanish speaking 46953 8

The solution is simply to use the . literal instead by escaping the character with backslashes:

System.err.println(convertPdfToText(save).split("3\\.8").length);