How to sort a String array

Question

I have an String array called myArray (for the sake of argument, let's just say it contains words from a story). I want to pass this array to a method that will sort them alphabetically and analyze the words. I've looked this up on SO and many people have suggested for this scenario to use java.util.Arrays.sort(myArray). So I used this line in my method, passed in myArray, and performed calculations on it, etc etc.

However, it recently came to my attention that this will permanently sort myArray. That is, the array will still be sorted after I come out of the method. Is there a way for me to only sort the array within the scope of the method?

Example code:

public static double uniqueWords(String[] doc1) {

    java.util.Arrays.sort(doc1)

    ... // count up the number of unique words in this array

    return COUNT_OF_UNIQUE_WORDS;
}

public static void main(String[] args) {
    String[] document;
    ... // put values in the array
    System.out.println(uniqueWords(document));
    System.out.println(java.util.Arrays.toString(document));   // here the array will still be sorted, which I DON'T want
}

Willem · Accepted Answer · 2012-11-12 19:19:35Z

8

String temp[] = java.util.Arrays.copyOf(doc1,doc1.length);
java.util.Arrays.sort(temp);

answered Nov 12, 2012 at 19:19

Willem

3762 silver badges8 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Yogendra Singh · Accepted Answer · 2012-11-12 19:34:59Z

4

Make a copy of the array, sort that copy and use the same.

  String [] sortedDocuments = new Sting[document.length];
  Systems.arraycopy(document, 0, sortedDocuments , 0, document.length);
  Arrays.sort(sortedDocuments );

or

  String [] sortedDocuments = Arrays.copyOf(document, document.length);
  Arrays.sort(sortedDocuments );

Use the sortedDocuments array with-in your method. Your original array document is left untouched.

edited Nov 12, 2012 at 19:34

answered Nov 12, 2012 at 19:19

Yogendra Singh

34.5k7 gold badges66 silver badges73 bronze badges

Comments

akuhn · Accepted Answer · 2012-11-12 19:22:56Z

1

If all you want to do is to count unique words, better use the following code. There's no need to sort your array to count unique elements.

public int countUniqueElements(Object[] array) {
    return new HashSet(Arrays.asList(array)).size();
}

answered Nov 12, 2012 at 19:22

akuhn

27.9k2 gold badges79 silver badges93 bronze badges

1 Comment

yiwei Over a year ago

yeah I knew that. I actually do more things that find unique words, I just wanted something simple to type so I wouldn't have to include ALL of my code haha. It was the first thing to come to mind. But thanks!

Collectives™ on Stack Overflow

How to sort a String array

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related