Java split函数给了我一小段结果String数组

Question

I have this code:

String string = "_a_b___";
String[] parts = string.split("_");

The result is that variable parts has only three elements

parts[0] = ""
parts[1] = "a" 
parts[2] = "b"

This is weird, because there are five "_" chars, so after splitting there should be six elements, not only three of them.

I want

parts[0] = ""
parts[1] = "a"
parts[2] = "b"
parts[3] = ""
parts[4] = "" 
parts[5] = "" 

How to do that? Thank you very much!

Answer 1

From Java documentation :-

Trailing empty strings are therefore not included in the resulting array.

Try split("_",6)

Answer 2

The solution of @Zakir is correct, i would add another information to use it perfectly, to get what you want instead of using split("_", 6) you can generalize it and use :

String[] parts = string.split("_", string.replace("(?!_)", "").length());

Which can accept any length.

for _a_b___ you will get [, a, b, , , ]

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Edit

Or like @Bill F mention in comment, you can also use String[] parts = string.split("_", -1); for any length as well. Java doc