Count the number of values in a String with .split(";")

Question

how can I sucessfully count the numbers of values in a String that are seperated through a semicolon(including empty values)?

I have for example this String:

;;C;D;E;F;G

The correct number of values would be '7', but when I use .split it returns the wrong number, because of the empty values.

How can I fix this?

`System.out.println(";;C;D;E;F;G".split(";").length);` prints `7` to me. — Pshemo, Mar 28 '16 at 13:56
It prints `7` to me also. There's certainly a mistake with the way you're counting elements. — Yassin Hajaj, Mar 28 '16 at 13:57
Ditto with the two above. I also get a length of 7. What is your method for counting the elements? — kevingreen, Mar 28 '16 at 13:59

score 3 · Accepted Answer · answered Mar 28 '16 at 14:06

Example from your question works fine since

System.out.println(";;C;D;E;F;G".split(";").length);

prints 7.

But problem could appear when empty elements are at end of your string like

System.out.println(";;C;D;E;F;G;;".split(";").length);

which also would return 7. Why is that? Because split(regex) uses split(regex,limit) version with limit set to 0. This limit represents behaviour of split in which trailing empty elements will be removed.

If you don't want to remove trailing empty elements use negative limit like

System.out.println(";;C;D;E;F;G;;".split(";", -1).length);
//                                            ^^-negative limit

which will now print 9.

Your mind reading power are strong ;) – Peter Lawrey Mar 28 '16 at 14:08 — Peter Lawrey, Mar 28 '16 at 14:08

score 2 · Answer 2 · edited Mar 28 '16 at 14:09

2

String#split() may return return a wrong number because of the empty values only if the separators are at the tail of text, e.g. ";;C;D;E;F;G;;". To avoid that use text.split(regex, -1)

edited Mar 28 '16 at 14:09

Alex Salauyou

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answered Mar 28 '16 at 14:04

Evgeniy Dorofeev

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Count the number of values in a String with .split(";")

2 Answers2