c******n
发帖数: 4965 | 1 【 以下文字转载自 Programming 讨论区 】
【 原文由 creation 所发表 】
I think I read somewher before that
the scopes of global variables in C are not cleanly defined
if you have multiple definitions of a variable in different files,
some compilers take them to be "static", some take as "global"
e.g. I have a.c, and b.c
////////////////////////////
// a.c
int n;
void fun();
void main(){
n=1;
fun();
printf("main: %d\n", n);
}
//////////////
// b.c
int n;
void fun(){
n=2;
///////////////////////////////// |
f*****p
发帖数: 235 | 2 Why not just try it out.
【在 c******n 的大作中提到】
: 【 以下文字转载自 Programming 讨论区 】
: 【 原文由 creation 所发表 】
: I think I read somewher before that
: the scopes of global variables in C are not cleanly defined
: if you have multiple definitions of a variable in different files,
: some compilers take them to be "static", some take as "global"
: e.g. I have a.c, and b.c
: ////////////////////////////
: // a.c
: int n;
|
c******n
发帖数: 4965 | 3 of course I know the results
just want to know the standards / or lack thereof
【在 f*****p 的大作中提到】
: Why not just try it out.
|
f*****p
发帖数: 235 | 4 No idea. If this is an interview question, it's bad.
【在 c******n 的大作中提到】
: of course I know the results
: just want to know the standards / or lack thereof
|
c******n
发帖数: 4965 | 5 I always use
extern/static for sure,
【在 f*****p 的大作中提到】
: No idea. If this is an interview question, it's bad.
|
f*****p
发帖数: 235 | 6 if u sure, why post?
【在 c******n 的大作中提到】
: I always use
: extern/static for sure,
|
c******n
发帖数: 4965 | 7 it's still allowable by standards!
many people write such code
【在 f*****p 的大作中提到】
: if u sure, why post?
|
v******d
发帖数: 1322 | 8 if u don't use extern, u cannot access the global
variable defined in the other files.
【在 c******n 的大作中提到】
: 【 以下文字转载自 Programming 讨论区 】
: 【 原文由 creation 所发表 】
: I think I read somewher before that
: the scopes of global variables in C are not cleanly defined
: if you have multiple definitions of a variable in different files,
: some compilers take them to be "static", some take as "global"
: e.g. I have a.c, and b.c
: ////////////////////////////
: // a.c
: int n;
|
c******n
发帖数: 4965 | 9 just try my example with gcc
【在 v******d 的大作中提到】
: if u don't use extern, u cannot access the global
: variable defined in the other files.
|
