How do I remove duplicate element from array?

This example demonstrates you how to remove duplicate elements from an array using the java.util.HashSet class.

package org.kodejava.example.util;

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class ArrayRemoveDuplicate {
    public static void main(String[] args) {
        // A string array with duplicate values
        String[] data = {
                "A", "C", "B", "D", "A", "B", "E", "D", "B", "C"
        System.out.println("Original array         : " +

        // Convert it to list as we need the list object to create a
        // set object. A set is a collection object that cannot have
        // a duplicate values, so by converting the array to a set
        // the duplicate value will be removed.
        List<String> list = Arrays.asList(data);
        Set<String> set = new HashSet<String>(list);

        System.out.print("Remove duplicate result: ");

        // Create an array to convert the Set back to array.
        // The Set.toArray() method copy the value in the set to the
        // defined array.
        String[] result = new String[set.size()];

Wayan Saryada

A programmer, runner, recreational diver, currently living in the island of Bali, Indonesia. Mostly programming in Java, creating web based application with Spring Framework, JPA, etc. If you need help on Java programming you can hire me on Fiverr.

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