Class Product

  • All Implemented Interfaces:
    java.util.function.DoubleConsumer, java.util.function.DoubleSupplier, java.util.function.IntSupplier, java.util.function.LongSupplier, DoubleStatistic, StatisticAccumulator<Product>, StatisticResult

    public final class Product
    extends java.lang.Object
    implements DoubleStatistic, StatisticAccumulator<Product>
    Returns the product of the available values.
    • The result is one if no values are observed.
    • The result is NaN if any of the values is NaN.

    This class is designed to work with (though does not require) streams.

    This instance is not thread safe. If multiple threads access an instance of this class concurrently, and at least one of the threads invokes the accept or combine method, it must be synchronized externally.

    However, it is safe to use accept and combine as accumulator and combiner functions of Collector on a parallel stream, because the parallel instance of Stream.collect() provides the necessary partitioning, isolation, and merging of results for safe and efficient parallel execution.

    Since:
    1.1
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private double productValue
      Product of all values.
    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private Product()
      Create an instance.
    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void accept​(double value)
      Updates the state of the statistic to reflect the addition of value.
      Product combine​(Product other)
      Combines the state of the other statistic into this one.
      static Product create()
      Creates an instance.
      double getAsDouble()
      Gets the product of all input values.
      static Product of​(double... values)
      Returns an instance populated using the input values.
      static Product of​(int... values)
      Returns an instance populated using the input values.
      static Product of​(long... values)
      Returns an instance populated using the input values.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
      • Methods inherited from interface java.util.function.DoubleConsumer

        andThen
    • Field Detail

      • productValue

        private double productValue
        Product of all values.
    • Constructor Detail

      • Product

        private Product()
        Create an instance.
    • Method Detail

      • create

        public static Product create()
        Creates an instance.

        The initial result is one.

        Returns:
        Product instance.
      • of

        public static Product of​(double... values)
        Returns an instance populated using the input values.

        The result is NaN if any of the values is NaN or the product at any point is a NaN.

        When the input is an empty array, the result is one.

        Parameters:
        values - Values.
        Returns:
        Product instance.
      • of

        public static Product of​(int... values)
        Returns an instance populated using the input values.

        When the input is an empty array, the result is one.

        Parameters:
        values - Values.
        Returns:
        Product instance.
      • of

        public static Product of​(long... values)
        Returns an instance populated using the input values.

        When the input is an empty array, the result is one.

        Parameters:
        values - Values.
        Returns:
        Product instance.
      • accept

        public void accept​(double value)
        Updates the state of the statistic to reflect the addition of value.
        Specified by:
        accept in interface java.util.function.DoubleConsumer
        Parameters:
        value - Value.
      • getAsDouble

        public double getAsDouble()
        Gets the product of all input values.

        When no values have been added, the result is one.

        Specified by:
        getAsDouble in interface java.util.function.DoubleSupplier
        Returns:
        product of all values.