String split() method, zero and negative limit

Question

http://www.tutorialspoint.com/java/java_string_split.htm

Here is the syntax of this method: public String[] split(String regex, int limit) or public String[] split(String regex)

In the above link, I can understand the Str.split("-", 2) and Str.split("-", 3) examples.

However, I don't quite get the Str.split("-", 0), what's the role of zero of the limit? In some examples, I have also encountered negative limits, what is this?

http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#split%28java.lang.String,%20int%29 — Syam S, Jul 11 '14 at 15:24
Copy-pasted for your convenience: "f n is non-positive then the pattern will be applied as many times as possible and the array can have any length.If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded." — laune, Jul 11 '14 at 15:27
@laune You missed the prior sentence! Not surprising, since *non-positive* isn't **obviously** negative. *If n is non-positive then the pattern will be applied as many times as possible and the array can have any length. If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.* So, a zero discard empty records and a negative preserves them! — Elliott Frisch, Jul 11 '14 at 15:28
@ElliottFrisch Yes, my scanner was definitely set too narrow ;-o Thanks. — laune, Jul 11 '14 at 15:31

GingerHead · Accepted Answer · 2014-07-11T15:48:26.870

21

The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array. We have 3 possible values for this limit:

If the limit n is greater than zero then the pattern will be applied at most n - 1 times, the array's length will be no greater than n, and the array's last entry will contain all input beyond the last matched delimiter.
If n is non-positive then the pattern will be applied as many times as possible and the array can have any length.
If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.

You can read more here.

edited Jul 11 '14 at 15:48

answered Jul 11 '14 at 15:26

GingerHead

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In n is zero, will leading empty strings be discarded too? 0:) before I test it... – Jul 11 '14 at 15:33
No unfortunately it will not, it will add an element holding one space! – GingerHead Jun 12 '19 at 18:28
Take a look at this method: – GingerHead Jun 12 '19 at 18:34
public String[] splitWithLead( String input, String limit ) { return input.replaceFirst("^" + limit, "").split(limit); } – GingerHead Jun 12 '19 at 18:35

score 9 · Answer 2 · edited Nov 29 '17 at 12:34

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Str.split("-",0) is the same as Str.split("-")

edited Nov 29 '17 at 12:34

soorapadman

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answered Jul 11 '14 at 15:26

dari

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score 2 · Answer 3 · answered Jul 11 '14 at 15:25

2

Str.split("-", 0) is equivalent to Str.split("-"). I.e, there's no limit.

answered Jul 11 '14 at 15:25

Eran

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String split() method, zero and negative limit

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