Java Program: Remove Duplicate Elements from List using Streams

Last update on April 28 2025 07:53:57 (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:

For more Practice: Solve these Related Problems:

• Write a Java program to remove duplicate integers from a list using streams and then sort the unique values in ascending order.
• Write a Java program to remove duplicate strings from a list using streams while ignoring case sensitivity.
• Write a Java program to remove duplicate elements from a list using streams and then count the total number of unique elements.
• Write a Java program to remove duplicates from a list of objects using streams based on a specified attribute.

Java Code Editor:

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