How to randomly access nth element in StringTokenizer

Question

Is there anyway we can directly access a certain(lets say 20th) element in a stringTokenizer. Every now and then I need only a certain element from it and do not need others, yet I have to traverse through all elements.

EDIT: I also want to ignore empty elements.

Am I missing something?

score 5 · Answer 1 · edited Aug 07 '14 at 18:33

5

You can use String.split for that instead of a Tokenizer.

For example:

String[] split = "you string is splitting".split(" ");
split[2];  // random access to the 3rd element of split

Of course, you will need to check that your split actually has that many elements before accessing its subindex.

edited Aug 07 '14 at 18:33

Xipo

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answered Nov 15 '11 at 14:34

Pablo Santa Cruz

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Can it split at multiple, different delimiters? – jem Nov 15 '11 at 14:35
Can it ignore empty elements? – jem Nov 15 '11 at 14:35
Yes, you can split at **any** regular expression you want. That will give you a lot of flexibility. – Pablo Santa Cruz Nov 15 '11 at 14:36
@SyedAqeel basically yes, you could, for example, split on `,` or `;` meaning `"a,b;c"` would result in `["a","b","c"]`. – Thomas Nov 15 '11 at 14:36
[http://download.oracle.com/javase/6/docs/api/java/lang/String.html#split(java.lang.String)] - link to split – Guillaume Nov 15 '11 at 14:38
What about ignoring empty elements? – jem Nov 16 '11 at 13:35

Thomas · Accepted Answer · 2011-11-15T14:47:31.303

You could try Apache Commons Lang's StringUtils class, which can split a string while ignoring empty elements and handling null strings for you.

A tokenizer would have to read at least n tokens in order to determine which is the n-th one. Thus it might be easier to just create a string array using String#split() or StringUtils.split(...).

Note that I'd prefer StringUtils.split(...) since it doesn't return empty elements if I don't want them, i.e. StringUtils.split(",a,b,c;;d,e,,f",";,"); would return ["a","b","c","d","e","f"] whereas String#split() would return ["","a","b","c","","d","e","","f"]

score 0 · Answer 3 · answered Nov 15 '11 at 14:37

0

Tokenizer is meant to access elements sequentially (kinda like a LinkedList). You have to go through all the tokens and store them in some kind of random-access collection (ArrayList), or use another method to split your original string / stream.

answered Nov 15 '11 at 14:37

Guillaume

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How to randomly access nth element in StringTokenizer

3 Answers3