How to remove duplicate value from array in java?

This article contains example of how to remove duplicate value from array in java with different different methods like using Set, using stream dicstinct funcation.

Example 1 : Remove duplicate value from array using Set

Set is contains unique and unorder values. Using Set Collection we can remove duplicate values, Let me clear here Set internally used HashMap as Key parameters. Its contains all characteristics  of HashMap Key attributes.

Using Java 7 traditional:

String[] names = {"Java", "C", "PHP", "Java", "Net", "C"};
HashSet<String> uniqueNames = new HashSet<>();
for (String name : names) {
 uniqueNames.add(name); // its will remove duplicate name because Set will set only unique value
}
for (String name : uniqueNames) {
 System.out.println(name);
}

Using Java 8 Stream

String[] names = {"Java", "C", "PHP", "Java", "Net", "C"};
java.util.Set<String> uniqueNames = Stream.of(names).collect(Collectors.toSet());
uniqueNames.forEach(System.out::println);

Output:

Java
C
PHP
Net

Example 2: Remove duplicate value from Array using Stream distinct

In Java 8 provide stream using that we can perform so many operation easily. distinct() is function which return unique object from Stream, after distinct we will convert those result to list.

String[] names = {"Java", "C", "PHP", "Java", "Net", "C"};
List<String> uniqueNames = Stream.of(names).distinct().collect(Collectors.toList());
uniqueNames.forEach(System.out::println);

Output:

Java
C
PHP
Net

Refer HashSet , java 8 stream for more details about HashSet and java 8 stream.