I define an array and a function. The array is defined outside of the function. But I also have to use this inside the function. What do I need to do?
uint8_t array[] = { 1, 2, 3, 4 };
myfunction(){
//call index #2 of array
}
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Jonathan Leffler
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M. Zim
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What do you mean by outside of the function?Global?In main? – Gaurav Sehgal Jun 29 '17 at 19:20
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3Functions can be called. Arrays cannot be called. Arrays can be accessed. We have yet to see a description of a problem or a question. – Mike Nakis Jun 29 '17 at 19:20
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You can't "call" an array. You can call a function. And yes, you can use a global variable inside a function. – Eugene Sh. Jun 29 '17 at 19:20
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What do you mean by "call" the array? You can refer to it: `a[2]`, and assign to it: `a[2] = 10`. – Lee Daniel Crocker Jun 29 '17 at 19:21
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Sorry for being unclear. But those two answers where the solution, global scope is the keyword. – M. Zim Jun 29 '17 at 19:31
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@M.Zim: It is not. The answerers are imprecise at best, technically they are wrong. There is no such thing like "global scope" in C. – too honest for this site Jun 30 '17 at 11:59
1 Answers
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Yes, you can do this. The array you declared has global scope, so it is available inside the function.
int arr[] = { 1, 2, 3, 4 };
void myfunction(){
printf("element is %d",arr[1]); //This is perfectly valid
}
Abhishek Ranjan
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I am also not the down voter, and I am not sure what compiler you are using, but when I create, and try to use `myfunction` with the form you have, it fails. I am using a C99 compiler. The prototype should be `void myfunction(void);`, (not `void myfunction();`). – ryyker Jun 29 '17 at 20:01
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@ryyker Are you using a C++ compiler or old C compiler. `void myfunction()` should be OK. – chux - Reinstate Monica Jun 29 '17 at 20:02
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@chux - I am using a 2017 implementation of C99 (ANSI C), it is a National Instruments implementation. The error msg may be because I have the "require prototypes" option set, and it does not recognize the prototype without the void in the parenthesis. I tried it both ways, it will not compiler without the `void` – ryyker Jun 29 '17 at 20:07
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1@ryyker [empty list in a function declarator that is part of a definition of that function specifies that the function has no parameters.](https://stackoverflow.com/a/12022875/2410359) may help. – chux - Reinstate Monica Jun 29 '17 at 20:11
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1@chux - good reference. And I tried it on my system with the prototype: `void func(void);`, but the definition: void func(){...}` and it did not complain. Since this answer is just showing the definition, I agree its perfectly valid. Thanks, – ryyker Jun 29 '17 at 20:17
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@Olaf I wrote it to make him understand that. What I meant was that the array is available globally – Abhishek Ranjan Jun 30 '17 at 05:19
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@AbhishekRanjan: It is not. You confuse scope and linkage. These are two different fundamental concepts of C. Unless you pointed out their difference, you add to OPs apparent confusion. – too honest for this site Jun 30 '17 at 11:57
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@Olaf In that case, I request you to edit my answer and all relevant content. It will help OP as well as me. – Abhishek Ranjan Jun 30 '17 at 15:01
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@AbhishekRanjan: This is not my answer and I will not answer for you; The standard is quite clear and not taht complicated to read. – too honest for this site Jun 30 '17 at 16:06