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Write a Java Program to Remove duplicate elements from ArrayList
PROGRAM: Java Program to Remove duplicate elements from ArrayList
/*Java Program to Remove duplicate elements from ArrayList*/
1: Remove duplicate elements from ArrayList using Set
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.Set;
class Main {
public static void main(String[] args) {
// create an arraylist from the array
// using asList() method of the Arrays class
ArrayList<Integer> numbers = new ArrayList<>(Arrays.asList(1, 2, 3, 4, 1, 3));
System.out.println(“ArrayList with duplicate elements: ” + numbers);
// convert the arraylist into a set
Set<Integer> set = new LinkedHashSet<>();
set.addAll(numbers);
// delete al elements of arraylist
numbers.clear();
// add element from set to arraylist
numbers.addAll(set);
System.out.println(“ArrayList without duplicate elements: ” + numbers);
}
}
2: Remove duplicate elements from ArrayList using Stream
import java.util.ArrayList;
import java.util.Arrays;
import java.util.stream.Collectors;
import java.util.stream.Stream;
class Main {
public static void main(String[] args) {
// create an arraylist from the array
// using asList() method of the Arrays class
ArrayList<Integer> numbers = new ArrayList<>(Arrays.asList(1, 2, 3, 4, 1, 3));
System.out.println(“ArrayList with duplicate elements: ” + numbers);
// create a stream from arraylist
Stream<Integer> stream = numbers.stream();
// call the distinct() of Stream
// to remove duplicate elements
stream = stream.distinct();
// convert the stream to arraylist
numbers = (ArrayList<Integer>)stream.collect(Collectors.toList());
System.out.println(“ArrayList without duplicate elements: ” + numbers);
}
}
