我一直只使用 Java 6,现在正赶上来学习 Java 8中的新功能.我在这里阅读这篇文章：
http://www.drdobbs.com/jvm/lambda-expressions-in-java-8/240166764?pgno=2

它说：

The Java API defines several generic functional interfaces in the
java.util.function package. One of the interfaces,BiFunction,describes functions with parameter types T and U and return type
R. You can save our string comparison lambda in a variable of that
type:

BiFunction comp
=(第一,第二) – > Integer.compare(first.length(),second.length());

However,that does not help you with sorting. There
is no Arrays.sort method that wants a BiFunction. If you have used a
functional programming language before,you may find this curIoUs. But
for Java programmers,it’s pretty natural. An interface such as
Comparator has a specific purpose,not just a method with given
parameter and return types. Java 8 retains this flavor. When you want
to do something with lambda expressions,you still want to keep the
purpose of the expression in mind,and have a specific functional
interface for it.

但是,当我看到这个帖子时：
How do you assign a lambda to a variable in Java 8?

那里的问题的答案建议完全按照引用的段落说你做不到的.

那么,文章中的信息是不正确的,还是我在这里读错了？

谢谢！

BiFunction<String,Integer> bifunc = (a,b) -> 
                               Integer.compare(a.length(),b.length());

Arrays.sort(array,bifunc::apply);