Array has incomplete element type. What does this mean? [duplicate]

Answer 1

To fix the printArray function you will need to include the array dimensions. In C, arrays are simply a block of elements, there is no length stored anywhere. The programmer would need to keep track of the length by some method.

For example:

// header
void printArray(int num, int arr[num][num]);

// source file
void printArray(int num, int arr[num][num])
{
    for(int i=0;i

For the multiplication function you will need to do something similar, the caller should allocate the array (e.g. int arr[num][num];) and then the function should fill in the values for the array cells.