自动生成变量 [英] Automatically generate variables
问题描述
您好，
我正在寻找一种自动在C中声明变量的方法。
我不确定是否有好方法要做到这一点，但我有点想要这样的东西
...
int i;
for（i = 1; i< 4; i ++）{
int variable ....
}
例如，这个循环会声明以下变量全部
类型int：
variable1
变量2
变量3
这样的事情可能吗？还有另一种方式吗？
提前致谢，
-Nate
Le 13-02-2007，Nate< nv ****** @sbcglobal.netaécrit*：
这样的事情可能吗？还有另外一种方法吗？
数组？
Marc Boyer
Nate< ; nv ****** @ sbcglobal.netwrote：
我正在寻找一种自动在C中声明变量的方法。
我不确定是否有一个很好的方法可以做到这一点，但我有一些
这样的想法...
不，没有好的办法。你的方式尤其错误。 C
不能那样工作。
int i;
for（i = 1; i< 4; i ++）{
int variable ....
}
这样的事情可能吗？还有另外一种方法吗？
是;有一种不好的（恕我直言）方式：
#define DECLARE1（type，var）类型var ## 1
#define DECLARE2（type，var ）DECLARE1（type，var）; \
类型var ## 2
#define DECLARE3（type，var）DECLARE2（type，var）; \
类型var ## 3
int main（void）{
DECLARE3（int，foo）;
返回0;
}
您可以使用其他一些产生尽可能多的#defines
程序（比如一个shell脚本）并将它们放在一个单独的头文件中。
另外，你可以告诉我们你真正*想做什么，我们
可能会建议一个更好的选择。
-
C. Benson Manica |我*应该*知道我在说什么 - 如果我
cbmanica（at）gmail.com |不，我需要知道。火焰欢迎。
Christopher Benson-Manica写道：
Nate< nv ****** @ sbcglobal.netwrote：
>我正在寻找一种在C中自动声明变量的方法。
我不确定是否有这样做的好方法，但我有一些这样的想法...
不，没有好的办法。你的方式尤其错误。 C
不能那样工作。
> int i;
> for（i = 1; i< 4; i ++）{
int variable ....
}
>这样的事情可能吗？还有另外一种方法吗？
是的;有一种不好的（恕我直言）方式：
#define DECLARE1（type，var）类型var ## 1
#define DECLARE2（type，var ）DECLARE1（type，var）; \
类型var ## 2
#define DECLARE3（type，var）DECLARE2（type，var）; \
类型var ## 3
或者[稍微]更易于维护的方式：
#define DECLARE（var，seq）var ## seq
>
int main（void）{
DECLARE3（int，foo）;
返回0;
}
int main（ void）
{
int DECLARE（foo，1）;
int DECLARE（foo，2）;
DECLARE（foo，1）= 10;
foo2 = 5;
printf（" foo1：％d foo2：％d \ n \\ n'，DECLARE（foo，1），foo2）;
返回（0）;
}
>
您可以使用其他一些
程序（比如一个shell脚本）生成尽可能多的#defines并将它们放入单独的头文件。
另外，你可以告诉我们你真正*想做什么，我们
可能会建议一个更好的选择。 />
Hello,
I am looking for a method to automatically declare variables in C.
I''m not sure if there is a good way to do this, but I had something
like this in mind...
int i;
for(i = 1; i < 4; i++){
int variable....
}
For example, this loop would declare the following variables all of
type int:
variable1
variable2
variable3
Is something like this possible? Is there another way?
Thanks in advance,
-Nate
解决方案Le 13-02-2007, Nate <nv******@sbcglobal.neta écrit*:Is something like this possible? Is there another way?An array ?
Marc Boyer
Nate <nv******@sbcglobal.netwrote:
I am looking for a method to automatically declare variables in C.
I''m not sure if there is a good way to do this, but I had something
like this in mind...No, theres no "good" way. Your way, in particular, is wrong. C
doesn''t work like that.
int i;
for(i = 1; i < 4; i++){
int variable....
}
Is something like this possible? Is there another way?Yes; there''s a bad (IMHO) way:
#define DECLARE1(type,var) type var##1
#define DECLARE2(type,var) DECLARE1(type,var); \
type var##2
#define DECLARE3(type,var) DECLARE2(type,var); \
type var##3
int main( void ) {
DECLARE3(int,foo);
return 0;
}
You could generate as many #defines as you please using some other
program (say a shell script) and put them in a separate header file.
Alternatively, you could tell us what you *really* want to do and we
can probably suggest a much better alternative.
--
C. Benson Manica | I *should* know what I''m talking about - if I
cbmanica(at)gmail.com | don''t, I need to know. Flames welcome.
Christopher Benson-Manica wrote:Nate <nv******@sbcglobal.netwrote:
>I am looking for a method to automatically declare variables in C.
I''m not sure if there is a good way to do this, but I had something
like this in mind...
No, theres no "good" way. Your way, in particular, is wrong. C
doesn''t work like that.
>int i;
>for(i = 1; i < 4; i++){
int variable....
}
>Is something like this possible? Is there another way?
Yes; there''s a bad (IMHO) way:
#define DECLARE1(type,var) type var##1
#define DECLARE2(type,var) DECLARE1(type,var); \
type var##2
#define DECLARE3(type,var) DECLARE2(type,var); \
type var##3Or the [slightly] more maintainable way:
#define DECLARE(var, seq) var##seq
>
int main( void ) {
DECLARE3(int,foo);
return 0;
}int main(void)
{
int DECLARE(foo, 1);
int DECLARE(foo, 2);
DECLARE(foo, 1) = 10;
foo2 = 5;
printf("foo1: %d foo2: %d\n", DECLARE(foo, 1), foo2);
return(0);
}
>
You could generate as many #defines as you please using some other
program (say a shell script) and put them in a separate header file.
Alternatively, you could tell us what you *really* want to do and we
can probably suggest a much better alternative.
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