While reading the k&r book I found an interesting example (at least for a noob like me) of what I think is a static locally scoped variable used in a good way:
So as you can see the function return a string, based on the input n. So for my little knowledge this make sense since a static variable is initialized just the first time, and it is scoped just in the current block. If nobody need to access this variable the thing make perfectly sense. And that make me think about an earlier QA episode of Hmh, when somebody asked about static const, that example can explain why static const can be used.
I hope somebody like me find that useful!
And please correct me if I'm wrong :)
see ya!
1 2 3 4 5 6 7 8 9 10 11 12 13 | char *month_name(int n)
{
static char *name[]=
{
"Illegal month",
"January", "February", "March",
"April", "May", "June",
"July", "August", "September",
"October", "November", "December"
};
return (n < 1 || n > 12) ? name[0] : name[n];
}
|
So as you can see the function return a string, based on the input n. So for my little knowledge this make sense since a static variable is initialized just the first time, and it is scoped just in the current block. If nobody need to access this variable the thing make perfectly sense. And that make me think about an earlier QA episode of Hmh, when somebody asked about static const, that example can explain why static const can be used.
I hope somebody like me find that useful!
And please correct me if I'm wrong :)
see ya!
Edited by rizoma
on
In this case it will be even better - compiler will notice that values you are initializing array are known at compile time. So it will move whole array to data segment and there will be no need to initialize anything in code the first time function is called.
Here's the output from gcc:
As you can see it references array with global symbol "name.1758" - no initialization is done in code.
Here's the output from gcc:
1 2 3 4 5 6 7 8 9 | month_name: leal -1(%rdi), %edx movl $.LC0, %eax cmpl $11, %edx ja .L1 movslq %edi, %rdi movq name.1758(,%rdi,8), %rax .L1: ret |
As you can see it references array with global symbol "name.1758" - no initialization is done in code.