从 forEach java 8 获取返回列表
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/32616271/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Getting return list from forEach java 8
提问by ford prefect
I am trying to use a stream for something and I think I have a conceptual misunderstanding. I am trying to take an array, convert it to a stream, and .forEach item in the array I want to run a function and return a list of the results of that function from the foreach.
我正在尝试将流用于某事，但我认为我有一个概念上的误解。我正在尝试获取一个数组，将其转换为流，以及数组中的 .forEach 项我想运行一个函数并从 foreach 返回该函数的结果列表。
Essentially this:
本质上是这样的：
Thing[] functionedThings = Array.stream(things).forEach(thing -> functionWithReturn(thing))
Is this possible? Am I using the wrong stream function?
这可能吗？我是否使用了错误的流函数？
回答by Tunaki
What you are looking for is called the mapoperation:
您正在寻找的称为map操作：
Thing[] functionedThings = Arrays.stream(things).map(thing -> functionWithReturn(thing)).toArray(Thing[]::new);
This method is used to mapan object to another object; quoting the Javadoc, which says it better:
该方法用于将一个对象映射到另一个对象；引用 Javadoc，它说得更好：
Returns a stream consisting of the results of applying the given function to the elements of this stream.
返回一个流，该流由将给定函数应用于此流的元素的结果组成。
Note that the Stream is converted back to an array using the toArray(generator)method; the generator used is a function (it is actually a method reference here) returning a new Thing array.
请注意，使用该toArray(generator)方法将 Stream 转换回数组；使用的生成器是一个函数（这里实际上是一个方法引用）返回一个新的 Thing 数组。
