Passing arrays, structs and functions as arguments to a function

You can pass an array or struct as an argument to a function in the same way as any other type:

int zero_array(double a[10]) { int i; for (i=0; i<10; i=i+1) { a[i] = 0.0; } } int main(void) { double a[10]; zero_array(a); }

Though structs are passed by value (see above for an explanation of `by value'), C's handling of arrays (see here) means that arrays are effectively passed `by reference'.

If you do not know the size of the array at compile-time, you can declare the function as:

int zero_array(double a[]) { /* .. */ }

but you will probably need to know the size of the array at runtime, and you are likely to end up with something like

int zero_array(double a[], int size_of_array) { /* .. */ }

You can also pass functions as arguments to a function, using function pointers.