Java – Remove Duplicate Number from Array

package JavaPrograms;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class RemoveduplicateArray {

	//
//  Remove duplicate entries from an array of long integers
//
//  davekw7x
//

    public static void main(String[] args)
    {
        //
        // A long integer array with some duplicated values
        //
        long [] longArray = { 11,0, 11, 22, 44, 55, 66, 77, 88, 0, 99, 77, 66, 42, 55, 66, 99, 11};

        System.out.println("Original array size = " + longArray.length);
        System.out.println("Original array            : " +
                Arrays.toString(longArray));

        //
        // Want to let Java convert the array to a Set, since
        // the Set object won't have duplicate entries.
        //
        // But first...
        //
        // Since the Set constructor needs a List (not an array),
        // "convert" the array to a List.
        //
        List<Long> longList = new ArrayList<Long>();
        for (int i = 0; i < longArray.length; i++)
        {
            longList.add(longArray[i]);
        }

        // Now, instantiate a Set with its constructor that has a List argument
        Set <Long> longSet = new HashSet<Long>(longList);

        //
        // Create an array of Long objects and use Set.toArray()
        // to "convert" the Set to the array.
        Long[] resultNoDups = new Long[longSet.size()];
        longSet.toArray(resultNoDups);

        // Finally, if we want an array of long ints rather
        // than an array of Long objects, create the array
        // and copy the values
        long [] finalArray = new long[resultNoDups.length];
        for (int i = 0; i < resultNoDups.length; i++) {
            finalArray[i] = resultNoDups[i];
        }

        // Taa-daa
        System.out.println("After removing duplicates : " +
                Arrays.toString(finalArray));

        System.out.println("Result array size = " + finalArray.length);
        System.out.println();
    }
}

 

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