（void）printf vs printf [英] (void) printf vs printf
问题描述
clcs
我注意到有人喜欢在printf调用之前添加（void），
喜欢：（void）printf（" Timeout\\\
"）;而其他人则不然。所以
有人可以告诉我是否有任何收益可以为printf添加
（无效）。
谢谢，
Whatluo。
Hi, c.l.cs
I noticed that someone like add (void) before the printf call,
like: (void) printf("Timeout\n"); while the others does''t. So
can someone tell me whether there any gains in adding
(void) to printf.
Thanks,
Whatluo.
推荐答案
文章< 11 ********* *************@g44g2000cwa.googlegroups .com> ;,
whatluo< wh ***** @ gmail.com>写道：
In article <11**********************@g44g2000cwa.googlegroups .com>,
whatluo <wh*****@gmail.com> wrote:
我注意到有人喜欢在printf调用之前添加（void），
喜欢：（void）printf（" Timeout \\\
"）;而其他人则不然。所以有人可以告诉我在printf中添加
（void）是否有任何好处。
I noticed that someone like add (void) before the printf call,
like: (void) printf("Timeout\n"); while the others does''t. So
can someone tell me whether there any gains in adding
(void) to printf.
它可以使编译器静音（或者支持 - 单独的lint程序）警告
表示函数的结果已被丢弃。
此外，如果程序员特别小心检查
错误条件在每个地方都可能出现错误，那么printf（）上的
a（无效）可能是一个缺少错误的信号
检查那一个陈述是故意的设计决定
而不是被忽视的东西。
-
历史是一堆碎片 - Laurie Anderson
It can silence a compiler (or stand-alone "lint" program) warning
that the result of a function has been thrown away.
Also, if the programmer is being particularily careful to check
error conditions at every place errors can occur, then
a (void) on the printf() can be a signal that the lack of error
checking on that one statement is a deliberate design decision
instead of something that was overlooked.
--
History is a pile of debris -- Laurie Anderson
文章< 11 ********************** @ g44g2000cwa.googlegroups .com>，
" whatluo" < WH ***** @ gmail.com>写道：
In article <11**********************@g44g2000cwa.googlegroups .com>,
"whatluo" <wh*****@gmail.com> wrote:
clcs
我注意到有人喜欢在printf调用之前添加（void），如：（void）printf （QUOT; Timeout\\\
"）;而其他人则不然。所以
有人可以告诉我在printf中添加
（void）是否有任何好处。
Hi, c.l.cs
I noticed that someone like add (void) before the printf call,
like: (void) printf("Timeout\n"); while the others does''t. So
can someone tell me whether there any gains in adding
(void) to printf.
printf返回一个值。
当函数返回一个值，程序员忽略代码时，我想知道原因。通常有两种解释：
程序员在忽略返回值时犯了一个错误，或者程序员
确实忽略了返回值。当你写的时候
printf（...）;
我不知道你是否想要忽略返回值。如果你
写的
（无效）printf（...）;
它告诉我那个程序员知道printf返回一个值，并且
有意识地决定忽略该值。做一些专业的
编程，尝试在一百万行其他人的b
代码中找到一些错误，你会欣赏这些东西。
printf returns a value.
When a function returns a value, and the programmer ignores the code, I
would want to know why. There are usually two explanations: The
programmer made a mistake ignoring the return value, or the programmer
did ignore the return value on purpose. When you write
printf (...);
I have no idea if you wanted to ignore the return value or not. If you
write
(void) printf (...);
it tells me that the programmer knew that printf returns a value, and
made a conscious decision to ignore that value. Do some professional
programming, try finding a few bugs in a million lines of other people''s
code, and you will appreciate such things.
Christian Bau< ch *********** @ cbau.freeserve.co.uk>写道：
＃文章< 11 ********************** @ g44g2000cwa.googlegroups .com> ;,
＃" whatluo" < WH ***** @ gmail.com>写道：
＃
＃>c.l.cs
＃>
＃>我注意到有人喜欢在printf调用之前添加（void），
＃>喜欢：（void）printf（" Timeout \ nn）;;而其他人则不然。所以
＃>可以有人告诉我是否有任何收益添加
＃> （void）to printf。
＃
＃printf返回一个值。
＃
＃当一个函数返回一个值，程序员忽略代码，我想知道为什么。通常有两种解释：
＃程序员忽略了返回值时出错，或者程序员
＃确实忽略了返回值。当你写这个
我经常注意到很多人检查printf的返回
而不是简单地查看终端窗口。
-
SM Ryan http：/ /www.rawbw.com/~wyrmwif/
留给天主教徒来破坏生存。
Christian Bau <ch***********@cbau.freeserve.co.uk> wrote:
# In article <11**********************@g44g2000cwa.googlegroups .com>,
# "whatluo" <wh*****@gmail.com> wrote:
#
# > Hi, c.l.cs
# >
# > I noticed that someone like add (void) before the printf call,
# > like: (void) printf("Timeout\n"); while the others does''t. So
# > can someone tell me whether there any gains in adding
# > (void) to printf.
#
# printf returns a value.
#
# When a function returns a value, and the programmer ignores the code, I
# would want to know why. There are usually two explanations: The
# programmer made a mistake ignoring the return value, or the programmer
# did ignore the return value on purpose. When you write
I routinely notice lots of people checking the return of printf
instead of simply looking at the terminal window.
--
SM Ryan http://www.rawbw.com/~wyrmwif/
Leave it to the Catholics to destroy existence.
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