How do I remove duplicate elements from a String Array in Java?

Using Java Collection framework API, the duplicate elements in a string array can be removed easily by converting the string array to List, creating a HashSet from the List that removes the duplicates and converting set to String array back. See the example below.

String[] data = { "a", "c", "b", "d","a", "c", "b", "d"};
System.out.println("Actual array: " + Arrays.toString(data));

List<String> strList = Arrays.asList(data);
Set<String> strSet = new HashSet<String>(strList);
String[] result = new String[strSet.size()];

strSet.toArray(result);

System.out.println("Array without duplicates: ");
for (String s : result) {
  System.out.print(s + ", ");
}

The above program can be shortened further as shown below.

String[] data = { "a", "c", "b", "d", "a", "c", "b", "d" };

data = new HashSet<String>(Arrays.asList(data)).toArray(new String[0]);

for (String s : data) {
	System.out.print(s + ", ");
}

Earn bitcoins upto $250 (free), invest in other Cryptocurrencies when you signup with blockfi. Use the referral link: Signup now and earn!

Using BlockFi, don't just buy crypto - start earning on it. Open an interest account with up to 8.6% APY, trade currencies, or borrow money without selling your assets.

Join CoinBase! We'll both receive $10 in free Bitcoin when they buy or sell their first $100 on Coinbase! Available in India also. Use the referral Join coinbase!

Invest now!!! Get Free equity stock (US, UK only)!

Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.

The Robinhood app makes it easy to trade stocks, crypto and more.

Webull! Receive free stock by signing up using the link: Webull signup.