How to pass a contiguous array as a parameter in C? - c

Question

I have created a contiguous array with random values (0-9), but I don't know how to pass it to a function that would print it.
Right now I'm simply iterating through the array inside the main function, whenever I need to print it. But I want to have a function for that, it would make my code cleaner.
A minimal code example is below:
#include <stdio.h>
#include <stdlib.h>
int **alloc_2d_int(int rows, int cols);
int main(int argc, char** argv){
int **matrix;
int i,j,size=3;
matrix = alloc_2d_int(size,size);
// generate the array
for (i=0; i<size; i++)
{
for (j=0; j<size; j++)
{
matrix[i][j] = rand() % 10;
}
}
// how I print the array right now
for (i=0; i<size; i++)
{
for (j=0; j<size; j++)
{
printf("[%d][%d]=%d\n", i,j,matrix[i][j]);
}
}
// this is how I want the printing to happen
print_arr(matrix,3);
}
int **alloc_2d_int(int rows, int cols) {
int *data = (int *)malloc(rows*cols*sizeof(int));
int **array= (int **)malloc(rows*sizeof(int*));
int i;
for (i=0; i<rows; i++)
array[i] = &(data[cols*i]);
return array;
}
void print_arr(int **array,int size)
{
int i,j;
for (i=0; i<size; i++)
{
for (j=0; j<size; j++)
{
printf("matrix[%d][%d]=%d\n", i,j,array[i][j]);
}
}
}
Error message:
conflicting types for ‘print_arr’ [enabled by default]

Answer 1

You forgot to add the declaration(prototype) of your function. In C language, by-default, the return type of a function is of int type. But for your print_arr() function, the return type is void. So, you get the conflict type error.
So, Declare the print_arr() function above the main() function. Like:
void print_arr(int **array,int size);

Answer 2

You haven't declared print_arr function before the main so it is not able to find it. Rest works smoothly.