Splitting a Java String by the pipe symbol using split("|")

Question

The Java official documentation states:

The string "boo:and:foo", for example, yields the following results with these expressions Regex Result :

{ "boo", "and", "foo" }"

And that's the way I need it to work. However, if I run this:

public static void main(String[] args){
        String test = "A|B|C||D";

        String[] result = test.split("|");

        for(String s : result){
            System.out.println(">"+s+"<");
        }
    }

it prints:

><
>A<
>|<
>B<
>|<
>C<
>|<
>|<
>D<

Which is far from what I would expect:

>A<
>B<
>C<
><
>D<

Why is this happening?

Possible duplicate of How to split a string in Java

KIBOU Hassan
– KIBOU Hassan

2017-05-02 13:13:24 +00:00
Commented May 2, 2017 at 13:13 — KIBOU Hassan
– KIBOU Hassan, Commented May 2, 2017 at 13:13

Wilfred Hughes · Accepted Answer · 2016-11-28 10:54:30Z

457

You need

test.split("\\|");

split uses regular expression and in regex | is a metacharacter representing the OR operator. You need to escape that character using \ (written in String as "\\" since \ is also a metacharacter in String literals and require another \ to escape it).

You can also use

test.split(Pattern.quote("|"));

and let Pattern.quote create the escaped version of the regex representing |.

edited Nov 28, 2016 at 10:54

Wilfred Hughes

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answered May 29, 2012 at 9:10

Jigar Joshi

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2 Comments

Jigar Joshi Over a year ago

It is, split() method takes regex and | is special character for reg ex

Däñish Shärmà Over a year ago

you are my second choice as a moderator on stack overflow. All the best.

Basil Bourque · Accepted Answer · 2019-10-01 20:12:35Z

43

Use proper escaping: string.split("\\|")

Or, in Java 5+, use the helper Pattern.quote() which has been created for exactly this purpose:

string.split(Pattern.quote("|"))

which works with arbitrary input strings. Very useful when you need to quote / escape user input.

edited Oct 1, 2019 at 20:12

Basil Bourque

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answered Jan 9, 2014 at 16:07

Aaron Digulla

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1 Comment

randers Over a year ago

Not shure when the transition was made, but in Java 8, one would use Pattern.quote().

DimaSan · Accepted Answer · 2016-09-01 09:16:34Z

6

Use this code:

public static void main(String[] args) {
    String test = "A|B|C||D";

    String[] result = test.split("\\|");

    for (String s : result) {
        System.out.println(">" + s + "<");
    }
}

edited Sep 1, 2016 at 9:16

DimaSan

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answered Sep 1, 2016 at 8:46

berliandi

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1 Comment

Pshemo Over a year ago

This solution is already pointed by accepted answer. No need to repeat it.

Simon · Accepted Answer · 2015-11-29 13:48:37Z

3

You could also use the apache library and do this:

StringUtils.split(test, "|");

answered Nov 29, 2015 at 13:48

Simon

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Comments

Laurel · Accepted Answer · 2016-11-05 02:08:15Z

3

You can also use .split("[|]").

(I used this instead of .split("\\|"), which didn't work for me.)

edited Nov 5, 2016 at 2:08

Laurel

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answered Nov 4, 2016 at 12:40

Homer

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3 Comments

Pshemo Over a year ago

Both versions should work fine. If one doesn't it suggest problem is somewhere else.

Pax Vobiscum Over a year ago

@Pshemo This does however add an interesting flavor, that some reserved symbols does not have to be escaped if put inside brackets.

CHan251 Nov 3 at 0:23

I also tried several alternative but for me on Java 25 only the "[|]" is working - thanks

Ryan Augustine · Accepted Answer · 2018-09-20 11:14:15Z

1

test.split("\\|",999);

Specifing a limit or max will be accurate for examples like: "boo|||a" or "||boo|" or " |||"

But test.split("\\|"); will return different length strings arrays for the same examples.

use reference: link

answered Sep 20, 2018 at 11:14

Ryan Augustine

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Comments

Stormy · Accepted Answer · 2013-08-20 11:02:05Z

-2

the split() method takes a regular expression as an argument

answered Aug 20, 2013 at 11:02

Stormy

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