Java LongStream skip() Method

The skip() method in Java, part of the java.util.stream.LongStream interface, is used to return a stream consisting of the remaining elements of the original stream after discarding the first n elements. This method is useful when you need to bypass a specific number of elements and process only the remaining elements.

Table of Contents

1. Introduction
2. skip() Method Syntax
3. Understanding skip()
4. Examples
   • Basic Usage
   • Using skip() with Other Stream Operations
5. Real-World Use Case
6. Conclusion

Introduction

The skip() method is an intermediate operation that returns a new stream consisting of the remaining elements of the original stream after discarding the first n elements. It is particularly useful for scenarios where you need to ignore a certain number of elements and process the rest of the stream.

skip() Method Syntax

The syntax for the skip() method is as follows:

LongStream skip(long n)

Parameters:

• n: The number of leading elements to skip.

Returns:

• A new LongStream consisting of the remaining elements after the first n elements.

Throws:

• This method does not throw any exceptions.

Understanding skip()

The skip() method processes the stream and discards the first n elements, returning a new stream with the remaining elements. This can be useful for pagination, processing subsets of data, or ignoring initial elements that are not needed for further processing.

Examples

Basic Usage

To demonstrate the basic usage of skip(), we will create a LongStream and use skip() to discard the first 3 elements.

Example

import java.util.stream.LongStream;

public class SkipExample {
    public static void main(String[] args) {
        LongStream stream = LongStream.of(1L, 2L, 3L, 4L, 5L);

        // Use skip() to discard the first 3 elements
        LongStream skippedStream = stream.skip(3);

        // Print the elements of the skipped stream
        skippedStream.forEach(System.out::println);
    }
}

Output:

4
5

Using skip() with Other Stream Operations

This example shows how to use skip() in combination with filtering and mapping.

Example

import java.util.stream.LongStream;

public class SkipWithFilterAndMapExample {
    public static void main(String[] args) {
        LongStream stream = LongStream.of(10L, 20L, 30L, 40L, 50L);

        // Use skip() to discard the first 2 elements, then filter and map
        LongStream processedStream = stream
            .skip(2)               // Discard the first 2 elements
            .filter(n -> n > 20)   // Keep elements greater than 20
            .map(n -> n / 10);     // Divide each element by 10

        // Print the elements of the processed stream
        processedStream.forEach(System.out::println);
    }
}

Output:

3
4
5

Real-World Use Case

Skipping Initial Data Points

In real-world applications, the skip() method can be used to ignore initial data points that are not needed for analysis or processing. For example, you might want to skip the first few transaction amounts if they are considered outliers.

Example

import java.util.stream.LongStream;

public class SkipTransactionsExample {
    public static void main(String[] args) {
        LongStream transactionAmounts = LongStream.of(1000L, 2000L, 1500L, 3000L, 2500L);

        // Use skip() to ignore the first 2 transaction amounts
        LongStream remainingTransactions = transactionAmounts.skip(2);

        // Print the remaining transaction amounts
        remainingTransactions.forEach(amount -> System.out.println("Transaction Amount: " + amount));
    }
}

Output:

Transaction Amount: 1500
Transaction Amount: 3000
Transaction Amount: 2500

Conclusion

The LongStream.skip() method is used to return a stream consisting of the remaining elements of the original stream after discarding the first n elements. This method is particularly useful for ignoring initial elements and processing the rest of the stream. By understanding and using this method, you can efficiently manage and process streams of values in your Java applications, ensuring that elements are skipped as needed.