Java string split function acting strange

Question

Hi guys, I am noticing strange behaviour when using the split() method in Java.

I have a string as follows: 0|1|2|3|4|5|6|7|8|9|10

String currentString[] = br.readLine().split("\\|");
System.out.println("Length:"+currentString.length);
for(int i=0;i < currentString.length;i++){
     System.out.println(currentString[i]);
}

This will produce the desired results:

Length: 11
0
1
2
3
4
5
6
7
8
9
10

However if I receive the string: 0|1|2|3|4|5|6|7|8||

I get the following results:

Length: 8
0
1
2
3
4
5
6
7
8

The final 2 empties are omitted. I need the empties to be kept. Not sure what i am doing wrong. I have also tried using the split in this manner as well. ...split("\\|",-1);

but that returns the entire string with a length of 1.

Any help would be greatly appreciated!

Answer 1

You need to use indexOf() and then substring() for this to work. I don't think you can empty string by using split() only.

Answer 2

IMO, I think this is the default behavior of split, Anyway please try this:

String currentString[] = br.readLine().replace("||","| |").split("\|"); System.out.println("Length:"+currentString.length); for(int i=0;i < currentString.length;i++){ System.out.println(currentString[i]); }

This has not been tested yet, but i think this should do the trick.

Answer 3

My Java is a little bit rusty, but shouldn't it be:

String currentString[] = "0|1|2|3|4|5|6|7|8||".split("\\|");
System.out.println("Length:"+currentString.length); 
for(int i = 0; i < currentString.length; i++)
{
  System.out.println(currentString[i]); 
} 

Answer 4

The default behavior of split is to not return empty tokens (because of a zero limit). Use the two parameter split method with a limit of -1 will give you all empty tokens in the return.

UPDATE:

Test code as follows:

public class Test {
    public static void main(String[] args) {
    String currentString[] = "0|1|2|3|4|5|6|7|8||".split("\\|", -1);
    System.out.println("Length:"+currentString.length); 
    for(int i=0;i < currentString.length;i++){ System.out.println(currentString[i]); }
  }
}

Output as follows:

Length:11
0
1
2
3
4
5
6
7
8
--- BLANK LINE --    
--- BLANK LINE --

The "--- BLANK LINE --" is put in by me to show that the return is blank. It is blank once for the empty token after 8| and once for the empty trailing token after the last |.

Hope this clears things up.

Answer 5

String.split() is weird.

Its extreme weirdness, in this and other ways, are some of the reasons why we made Splitter.

It has less surprising behavior and lots of flexibility.