Passing entire Array as a parameter into a function - c

Question

I am trying to pass an entire array into a my function, but I am getting currently getting the error:
test.c: In function 'main':
test.c:4:18: error: expected expression before ']' token
method(myArray[]);
^
test.c: At top level:
test.c:8:6: warning: conflicting types for 'method' [enabled by default]
void method(int arr[]){
^
test.c:4:3: note: previous implicit declaration of 'method' was here
method(myArray[]);
^
test.c: In function 'method':
test.c:9:3: warning: incompatible implicit declaration of built-in function 'printf' [enabled by default]
printf("DATA: %d",arr[2]);
^
This is my code (a simplified version of what I'm trying to do that throws up the same error:
int main(){
int myArray[3];
myArray[2]=12;
method(myArray[]);
}
void method(int arr[]){
printf("DATA: %d",arr[2]);
}

Answer 1

When passing an array to a function, you don't need the [] after it. Just using the name of the array is sufficient.
Also, you need to either define or declare your functions before they're used, and you need to #include <stdio.h> so the compiler knows the definition of printf.
#include <stdio.h>
void method(int arr[]);
int main(){
int myArray[3];
myArray[2]=12;
method(myArray);
}
void method(int arr[]){
printf("DATA: %d",arr[2]);
}

Answer 2

More than one point to be mentioned here,
Firstly, include the required header files which contains the function signature of the library functions you're going to use.
Secondly, either forward declare the function prototype or define the function before usage. Be aware, the ancient implicit declaration rule has been officially dropped from the C standards.
Thirdly, change
method(myArray[]);
to
method(myArray);
as the array name itself gives you the base address of the array, which is basically what you need to pass.