Wednesday, September 29, 2021

Java Stream - skip() With Examples

In Java Stream API skip(long n) method is used to skip the first 'n' elements of the stream and return a stream consisting of the remaining elements of this stream.

Java Stream skip() method

Syntax of the skip method is as given below-

Stream<T> skip(long n)

Here n represents the number of leading elements to skip.

Method returns a new stream consisting of the remaining elements of this stream after skip operation. Since a new stream is returned that means skip() is a stateful intermediate operation.

If n is passed as a negative number, then IllegalArgumentException is thrown.

If this stream contains fewer than n elements then an empty stream will be returned.

skip() Java examples

1. To get a sublist from a List using skip method.

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

public class StreamSkip {

  public static void main(String[] args) {
    StreamSkip ss = new StreamSkip();
    // Get sublist from the list of Integers
    List<Integer> numList = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
    List<Integer> subList = ss.getSubList(numList, 4);
    System.out.println("Sublist after skipping elements- " + subList);
    
    // Get sublist from the list of Strings
    List<String> strList = Arrays.asList("one", "two", "three", "four",
        "five","six","seven","eight","nine","ten");
    List<String> strSubList = ss.getSubList(strList, 5);
    System.out.println("Sublist after skipping elements- " + strSubList);
  }

  public <T> List<T> getSubList(List<T> firstList, long n){
    return firstList.stream().skip(n).collect(Collectors.toList());
  }
}

Output

Sublist after skipping elements- [5, 6, 7, 8, 9, 10]
Sublist after skipping elements- [six, seven, eight, nine, ten]

2. If n is greater than the stream size

public class StreamSkip {

  public static void main(String[] args) {
    StreamSkip ss = new StreamSkip();
    List<Integer> numList = Arrays.asList(1, 2, 3, 4, 5, 6);
    List<Integer> subList = numList.stream().skip(7).collect(Collectors.toList());     
    System.out.println("Sublist after skipping elements- " + subList);
  }
}

Output

Sublist after skipping elements- []

As you can see an empty stream is returned because elements you are trying to skip is more than the size of the stream itself.

That's all for this topic Java Stream - skip() With Examples. If you have any doubt or any suggestions to make please drop a comment. Thanks!

>>>Return to Java Advanced Tutorial Page


Related Topics

  1. Stream API in Java 8
  2. Java Stream - limit() With Examples
  3. collect() Method And Collectors Class in Java Stream API
  4. Spliterator in Java
  5. Java Stream API Interview Questions And Answers

You may also like-

  1. New Date And Time API in Java With Examples
  2. StringJoiner Class in Java 8
  3. JShell in Java With Examples
  4. Private Methods in Java Interface
  5. Lambda Expressions in Java 8
  6. Convert float to int in Java
  7. Spring MVC Configuring Multiple View Resolvers Example
  8. NgNonBindable Directive in Angular

No comments:

Post a Comment