java Java 中的 OptionalDouble stream()方法，带示例

Java 中的 OptionalDouble stream()方法，带示例

原文:https://www . geesforgeks . org/optionalduble-stream-method-in-Java-with-examples/

stream() 方法帮助我们获得由optionalduble作为 DoubleStream 包含的双值。如果存在一个值，则方法返回一个仅包含该值的连续双流，否则返回一个空双流。

语法:

public DoubleStream stream()

参数:此方法不接受任何内容。

返回值:该方法将可选值作为双流返回。

以下节目举例说明 stream()方法: 节目 1:

// Java program to demonstrate
// OptionalDouble.stream() method

import java.util.OptionalDouble;
import java.util.stream.DoubleStream;

public class GFG {

    public static void main(String[] args)
    {

        // create a OptionalDouble
        OptionalDouble opDouble
            = OptionalDouble.of(.3203);

        // get value as stream
        DoubleStream out = opDouble.stream();

        // print value
        System.out.print("Value: ");
        out.forEach(System.out::print);
    }
}

输出:

程序 2:

// Java program to demonstrate
// OptionalDouble.stream() method

import java.util.OptionalDouble;
import java.util.stream.DoubleStream;

public class GFG {

    public static void main(String[] args)
    {

        // create a empty OptionalDouble
        OptionalDouble opDouble
            = OptionalDouble.empty();

        // get value as stream
        DoubleStream out = opDouble.stream();

        // print value
        System.out.print("length of Double Stream: "
                         + out.count());
    }
}