由网友(许你一座花开不败的城)分享简介：流 接口对方法 of() 有两个重载.其中一个是可变参数方法，而另一个采用单个参数.The Stream interface has two overloads for the method of(). One of these is a variable-arity method while the other t...

流 接口对方法 of() 有两个重载.其中一个是可变参数方法，而另一个采用单个参数.

The Stream interface has two overloads for the method of(). One of these is a variable-arity method while the other takes a single argument.

与将一个参数传递给可变参数方法相比，单参数方法是一种性能优化吗?如果是这样，它如何提高性能?可以对 empty() 方法提出相同的问题，这似乎是可变参数 of() 周围的语法糖.

Is the single-argument method a performance optimization versus passing one argument to the variable-arity method? If so, how does it improve performance? The same questions could be asked of the empty() method, which would seem to be syntax sugar around the variable-arity of().

我发现这些方法的实现方式不同，区别显然在于 Spliterator 的实例化方式；但这对 Stream API 有什么好处?

I see that the implementation differs between these methods, with the difference apparently being how the Spliterator is instantiated; but what advantage does this offer to the Stream API?

推荐答案

是的，这是一种优化，可以避免创建一个只包含单个元素的数组的开销，如果你使用 varargs 版本，你会得到这样的结果.

Yes, it's an optimization to avoid the overhead of creating an array to hold only a single element, which is what you'd get if you used the varargs version.

empty() 方法也可以问同样的问题，这似乎是围绕可变参数 of() 的语法糖

The same questions could be asked of the empty() method, which would seem to be syntax sugar around the variable-arity of()

您在看什么实施版本?当我查看实现时，我看不到这一点.

What implementation version are you looking at? When I look at the implementation I don't see this.