extern « integer « C Data Type Q&A

1. Difference between extern int a; extern int a=42;    stackoverflow.com

While I was reading the answers of Use of 'extern' keyword while defining the variable One of the user answered these way

 extern int a;      ...

2. Undefined reference to extern int stm32    stackoverflow.com

I'm using Atrollic Studio(problem also exists in Eclipse). .h file

 extern int i2cInitIO(uint channel, uint hz);
 extern int i2cIO(uint device, byte *put, uint putlen, byte *get, uint getlen);

#include "tollosI2C.h"
int i2cGetReg(uint device, ...

3. int arr[10]; //in file1.c extern int *arr; //in file2.c main() { arr[0]=1; } //    bytes.com

your declaration extern int *arr; does not match the definition int arr[10]; Which is why you should put the declaration into a header file and then include that header into both C files. In all likely hood the reason you get an undefined reference to arr is either that you only linked with the object from compiling file2.c or that the ...

4. extern int *a , int a[10]    bytes.com

hi, check out the following program ... a.c ----- extern void fun(); int a[10]; int main () { fun (); } b.c ----- extern int *a; void fun() { a++; printf ("%d",a); } If i compile the above two files together ... what should be the behavior of variable a in fun() , it should be pointing to the array right ...

5. 'snprintf' undefined; assuming extern returning int    cboard.cprogramming.com

6. where from extern int errno came ?    cboard.cprogramming.com