Java: split() method with pipe special character

Question

I have a String = \"Hello-new-World\". And when i use the split() method with different regex values, it acts differently.

String str = \"Hello-new-world\"
Strin         


        

Answer 1

It is a metacharacter. Escape it with a backslash, like this: "\\|"

Answer 2

Pipe is special regex symbol which means OR, if you want to split by pipe then escape it in your regex:

String[] strbuf = str.split("\\|");

OR

String[] strbuf = str.split("[|]");

Answer 3

Presumably you're splitting on "|" in the second case - and | has a special meaning within regular expressions. If you want to split on the actual pipe character, you should escape it:

String[] bits = whole.split(Pattern.quote("|"));

Answer 4

str.split("|");

means something different. String#split uses regex, and | is a metacharacter, so that string means: split off of the empty string or off of the empty string. That is why your string gets split on every character.

There are a few ways of doing what you expect (use these as the string to split off of):

"\\|"

Which means to escape the metacharacter.

"[|]"

Puts the metacharacter in a character class.

"\\Q|\\E"

Puts the metacharacter in a quote

Answer 5

split method takes regular expression as input. The pipe is a special character for regular expression, so if you want to use it tou need to escape the special character. Ther are multiple solutions:

You need to escape the "pipe" character

str.split("\\|");

Or you can use the helper quote:

str.split(Regexp.quote("|"))

Or between sqares:

str.split("[|]");

Answer 6

The pipe has different meaning in regular expression, so if you want to use it you need to escape the special character.

str.split("\\|");