头文件问题 [英] Header files question
问题描述
嗯,K& R终于得到头文件!!!
我可以问这个问题。 (已查看常见问题解答)
我正在使用Xcode编译程序,所以很可能这个
做了一些奇怪的事情。
头文件有什么独特之处?
例如,如果我这样定义一个整数:
i = 96;
我可以使用i,例如main.c而没有先声明它(使用
extern i),如果是这样,是什么让头文件不同说,
" other_file.c"具有相同的定义?
提前致谢。
Well, K& R has finally gotten to header files!!!
May I ask this. (Have checked out the FAQ)
I am using "Xcode" to compile the program, so it may well be that this
is doing something strange.
What is unique to a header file?
For example, if I define an integer thus:
i=96;
can I use i in, for example main.c without first declaring it (using
extern i), and if so, what makes the header file diffferent from say,
"other_file.c" with the same definition?
Thanks in advance.
推荐答案
我的意思是 int i = 96;
mdh写道:
I meant "int i=96;
mdh wrote:
嗯,K& R终于得到头文件!!!
我可以问这个问题。 (已查看常见问题解答)
我正在使用Xcode编译程序,所以很可能这个
做了一些奇怪的事情。
头文件有什么独特之处?
例如,如果我这样定义一个整数:
int i = 96;
我可以使用i在,例如main.c而没有首先声明它(使用
extern i),如果是这样,是什么使得头文件不同说,
" other_file。 C"具有相同的定义?
提前致谢
Well, K& R has finally gotten to header files!!!
May I ask this. (Have checked out the FAQ)
I am using "Xcode" to compile the program, so it may well be that this
is doing something strange.
What is unique to a header file?
For example, if I define an integer thus:
int i=96;
can I use i in, for example main.c without first declaring it (using
extern i), and if so, what makes the header file diffferent from say,
"other_file.c" with the same definition?
Thanks in advance.
mdh写道:
mdh wrote:
我的意思是int i = 96;
mdh写道:
I meant "int i=96;
mdh wrote:
>好吧,K& R终于得到了头文件!!!
请问这个问题。 (已查看常见问题解答)
我正在使用Xcode编译程序,所以很可能这个做了一些奇怪的事情。
头文件有什么独特之处?
>Well, K& R has finally gotten to header files!!!
May I ask this. (Have checked out the FAQ)
I am using "Xcode" to compile the program, so it may well be that this
is doing something strange.
What is unique to a header file?
很少。这非常类似于你将所有内容放在.c文件中的代码
而不是说#include" myheader.h"
Little. It is very much like if you had placed everything in the code
in your .c file instead of saying #include "myheader.h"
>例如,如果我这样定义一个整数:
int i = 96;
我可以吗使用i in,例如main.c而不首先声明它(使用
extern i),如果是这样,是什么使得头文件不同说,
" other_file.c"有相同的定义?
>For example, if I define an integer thus:
int i=96;
can I use i in, for example main.c without first declaring it (using
extern i), and if so, what makes the header file diffferent from say,
"other_file.c" with the same definition?
没什么。如果你包含一个定义超过
一个.c文件的头文件,你得到多个定义 - 你不想要的。
完全定义它你的一个.c文件,如果你需要
使其可用于其他.c文件,你可以例如在头文件中放置一个
声明(使用extern关键字)
你需要包含的地方。
Nothing. If you include a header file with a definition in more than
one .c file, you get mutiple definition - which you don''t want.
Define it in exactly one of your .c files, and if you need to
make it available to other .c files, you can e.g. place a
declaration (use the extern keyword) in a header file which
you include where needed.
mdh写道:
mdh wrote:
嗯,K& ; R终于得到头文件!!!
我可以问这个问题。 (已查看常见问题解答)
Well, K& R has finally gotten to header files!!!
May I ask this. (Have checked out the FAQ)
头文件有什么独特之处?
What is unique to a header file?
Nils O. Sel?sdal写道:
Nils O. Sel?sdal wrote:
很少。这非常类似于你在.c文件中的代码中放置了所有内容而不是说#include" myheader.h"
Little. It is very much like if you had placed everything in the code
in your .c file instead of saying #include "myheader.h"
int i = 96;我可以使用i,例如main.c而不首先声明它(使用
extern i),如果是这样,是什么让头文件不同说,
" other_file.c"有相同的定义?
int i=96; can I use i in, for example main.c without first declaring it (using
extern i), and if so, what makes the header file diffferent from say,
"other_file.c" with the same definition?
没什么。 ...............在头文件中放置一个声明(使用extern关键字)
你需要包含哪些内容。
Nothing. ............... place a declaration (use the extern keyword) in a header file which
you include where needed.
所以Nils,你在说什么?
头文件中的声明?
other_c_files中的定义?
因此,名称是.h。简单地说方便如果你有一个庞大的
程序,它可以让调试等更容易,或者如果有多个人在工作吗?根据你的说法,你可以将所有声明放在
中说,my_specialfile.c,在必要时使用#include,但它会不会那么清楚?
谢谢
So Nils, what you are saying? is
Declarations in the header file?
Definitions in other_c_files?
So, is the designation ".h" simply "convenience" if you have a massive
program, it makes it easier debugging etc or if multiple people are
working on it? From what you say, you could put all declarations in
say, "my_specialfile.c", use # include where necessary, but it would
not be as clear?
Thanks
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