Question

Possible Duplicate:
Java – Distinct List of Objects

i have a sorted array of huge size (around 3000 strings) ,
i need to create an object for each distinct string ,
therefore i need create an array of objects with the size equal to distinct strings in the original array.

any suggestions?

Thanks

Answer 1

Well, if you need the distinct elements and not just the number, you may use a Set.

A Set is:

A collection that contains no duplicate elements.

You keep adding your elements to the set, and then just look at what the set contains.

Something similar to this:

public static String[] getDistinct(String[] input) {

    Set<String> distinct = new HashSet<String>();
    for(String element : input) {
        distinct.add(element);
    }

    return distinct.toArray(new String[0]);
}

Usage:

String[] input = new String[] {"a", "b", "a", "c", "a", "b", "d"};
String[] distinct = getDistinct(input);

for(String element : distinct) {
    System.out.println(element);
}

Result:

d b c a

Note that the order of the elements may not be preserved.

To find the number of the distinct elements, use:

getDistinct(input).length