Hi I'm having issues with the code below (file is of the File class):
String[] fileNameSplit = file.getName().split(".");
String fileType = fileNameSplit[(fileNameSplit.length - 1)];
It always throws a ArrayOutOfBoundsExecption at -1 suggesting that fileNameSplit is 0. When I take out the -1 it still says ArrayOutOfBoundsException but now at 0, meaning it is empty.
What am I doing wrong?
This is because . is a meta-character that accepts "any character". It treats every single character of your string as a delimiter, "eating up" its entire content.
Escape the dot it like this:
String[] fileNameSplit = file.getName().split("\\.");
or use a character class, like this:
String[] fileNameSplit = file.getName().split("[.]");
Use \\.
String[] fileNameSplit = file.getName().split("\\.");
As regex and String don't go well with each other, 1st \ is needed to be used to make the compiler realize that its not a dot(.) but a regex, and 2nd \ to make the java compiler take \ as literally.
\\. is the most common way of doing it..so i mentioned it... well whats done is done... fine... but thanks for that upvote...Note that the argument to the split method is a regex. In the regex, the dot has a special meaning: match any character.
To use the dot literally, you'll need to escape it:
`String[] fileNameSplit = file.getName().split("\\.");`
docs for the split method.
