在你看来，你遇到过的最令人惊讶、最怪异、最奇怪或最“WTF”的语言特性是什么?
请每个回答只回答一个特征。
当前回答
在C或c++中，使用宏可以获得很多乐趣。如
#define FOO(a,b) (a+b)/(1-a)
如果传入FOO(bar++，4)，它将使a增加两次。
其他回答
Java源文件可以以字符\u001a (control-Z)结尾。
我肯定会给Perl提供多个可怕的例子:
if(!$#var)
or
if($mystring =~ m/(\d+)/) {
我最喜欢的奇怪的C语言是5[“Hello World”]，但因为已经发布了，我最喜欢的第二个奇怪的是Windows版本结构初始化黑客:
void someWindowsFunction() {
BITMAPINFOHEADER header = {sizeof header};
/* do stuff with header */
}
这条微妙的线条达到了以下效果:
Declares a BITMAPINFOHEADER structure Concisely sets the "size" member of the structure, without hardcoding a size constant (since many Window structures, including BITMAPINFOHEADER, follow the convention of specifying the size of the structure as the first member} Declares the version of the structure (since many Windows structures, including BITMAPINFOHEADER, identify their version by the declared size, following the convention that structures definitions are append-only) Clears all other members of the structure (a C standard behavior when a structure is incompletely initialized).
在Perl中，可以通过修改一个类的@ISA数组来改变它的继承链，这让我很惊讶。
package Employee;
our @ISA = qw(Person);
# somwhere far far away in a package long ago
@Employee::ISA = qw(Shape);
# Now all Employee objects no longer inherit from 'Person' but from 'Shape'
不知道有没有人提过。
在Java中，在finally块中它可以返回一个值。它将停止异常的传播并覆盖正常的return语句。
