引用C11标准:
Array subsripting (§ 6.5.2.1)
The definition of the subscript operator
[]
is thatE1[E2]
is identical to(*((E1)+(E2)))
.
我想知道为什么E1周围的括号是必要的(它们在C89标准中缺失),即哪个表达式可以(*(E1(E2)))不同于(*((E1)(E2))) ?
解决方法
根据
http://www.open-std.org/jtc1/sc22/wg14/www/docs/n841.htm,为了清楚起见插入它.这两个表达式在语法上是等价的.
Public Comment Number PC-UK0103
Comment 1.
Category: Editorial change/non-normative contribution
Committee Draft subsection: 6.3.2.1
Title: Array subscripting example
Detailed description:Paragraph 2 should replace “
(*(E1+(E2)))
” by “(*((E1)+(E2)))
“,to avoid confusion. Yes,I know that the syntactic chart makes it quite unambiguous,but the current wording in paragraph 2 is very confusing.