Java Program: Remove Duplicate Elements from List using Streams

Last update on December 21 2024 10:02:14 (UTC/GMT +8 hours)

Write a Java program to remove all duplicate elements from a list using streams.

Sample Solution:

Java Code:

import java.util.Arrays;
import java.util.List;
import java.util.stream.Collectors;

public class Main {
  public static void main(String[] args) {
    List < Integer > nums = Arrays.asList(10, 23, 22, 23, 24, 24, 33, 15, 26, 15);
    System.out.println("Original List of numbers: " + nums);
    // Remove duplicates
    List < Integer > distinctNumbers = nums.stream()
      .distinct()
      .collect(Collectors.toList());
    System.out.println("After removing duplicates from the said list: " + distinctNumbers);
  }
}

Sample Output:

Original List of numbers: [10, 23, 22, 23, 24, 24, 33, 15, 26, 15]
After removing duplicates from the said list: [10, 23, 22, 24, 33, 15, 26]

Explanation:

In the above exercise,

• The list of numbers is defined as nums and initialized with the Arrays.asList method.
• The distinct method is applied to the stream of numbers using the stream method on the nums list.
• This operation removes duplicate elements from the stream.
• The resulting stream is collected back into a list using the collect method with Collectors.toList().

Flowchart:

Java Code Editor:

Improve this sample solution and post your code through Disqus

Previous: Sum of Even and Odd Numbers in a List using Streams.
Next: Count Strings Starting with Specific Letter using Streams.