What is DoubleStream.mapToObj method in Java?

Overview

The mapToObj() is a method of DoubleStream interface used to return an object-valued stream containing the results of applying the implementation of the DoubleFunction functional interface.

Note: mapToObj() is an intermediate operation. These operations are lazy. Intermediate operations run on a Stream instance, and when they’re done, they return a Stream instance as an output.

Syntax

<U> Stream<U> mapToObj(DoubleFunction<? extends U> mapper);

Parameters

DoubleFunction<? extends U> mapper: The implementation of the DoubleFunction interface.

Return value

This method returns a new object-valued stream.

Code

import java.util.stream.DoubleStream;
import java.util.stream.Stream;
class Main {
    public static void main(String[] args)
    {
        // Create a DoubleStream using the of method
        DoubleStream stream = DoubleStream.of(2.1, 4.5, 2.5);
        // Using DoubleStream mapToObj(DoubleFunction mapper)
        // create a new stream
        // to store the hexadecimal representation of the
        // elements in DoubleStream
        Stream<String> hexStream = stream.mapToObj(Double::toHexString);
        // Print an object-valued Stream
        hexStream.forEach(System.out::println);
    }
}