CODEWITHSUNDEEP
javastringsplit
Andreu Alcon
Andreu Alcon

Reputation: 217

Splitting a String with the pipe symbol as delimiter

Why is it that in the following, the output is [] and not [1]?

String input="1|2|3";
String[] values= input.split("|");
System.out.println("[" + values[0] + "]");
// Output: []

However, if we change the separator, the output is [1].

String input="1;2;3";
String[] values= input.split(";");
System.out.println("[" + values[0] + "]");
// Output: [1]

Upvotes: 15

Views: 2821

Answers (6)

user
user

Reputation: 3088

Try to escape that character:

String input="1|2|3";
String[] values= input.split("\\|");
System.out.println("[" + values[0] + "]");

Upvotes: 24

shartelle
shartelle

Reputation: 95

The pipe character is the equivalent to the logical or in a regex. If you really want to use the pipe character as separator, you need to escape it with a \ as in

String[] values= input.split("\|");

Upvotes: -2

aa8y
aa8y

Reputation: 3942

Try using \\| instead of | when you split as you need to escape it.

So your code would change to:

String input="1|2|3";
String[] values= input.split("\\|");
System.out.println("[" + values[0] + "]");

Upvotes: 4

Hussain Akhtar Wahid 'Ghouri'
Hussain Akhtar Wahid 'Ghouri'

Reputation: 6617

you have to escape the character '|' properly

String input="1|2|3";
        String[] values= input.split("\\|");
        System.out.println("[" + values[0] + "]");

Upvotes: 3

Fritz
Fritz

Reputation: 10055

The split method receives a regex as a parameter. The pipe is a reserved character with its own purpose (it means or).

You can either escape it ("\\|") or, if you're in Java 1.5+ you can use Pattern.quote("|") like this:

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

Upvotes: 6

Mike Dinescu
Mike Dinescu

Reputation: 55760

Because the | has special meaning in regular expressions. You need to escape it like this: \| and in Java you also have to escape the backslash as well so you end up with \\|

The pipe character is a disjunction operator which means that it tells the regular expression engine to choose either pattern on the left and right of it. In your case those where empty strings which match anything.

Upvotes: 15

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