呵呵,这个问题和编译器有关,你可以在不同的编译器下测试,可能会得到不同的结果,
-----------------------------------------------------------------------------
不是编译器相关,而是标准有说明的 (摘自Expert C)
z = y+++x;
The programmer might have meant z = y + ++x, or equally could have had z = y++
+ x in mind. The ANSI standard specifies a convention that has come to be known as the maximal munch strategy. Maximal munch says that if there's more than one possibility for the next token, the compiler will prefer to bite off the one involving the longest sequence of characters. So the above example will be parsed as z = y++ + x.