c - How to free a two dimensional array allocated memory using int ** ptr -

how free 2 dimensional array using function allocated memory using int ** ptr?

for example use allocarray( &ptrarray, row, column); allocate array. proper procedure free allocated memory using function: void freearray( int *** pa, int row, int column)

#include <stdio.h> #include <stdlib.h>  void allocarray( int *** pa, int row, int column) {     int i, j, count;      *pa = (int **) malloc(row * sizeof(int *));     (int =0; i<row; ++i)     {         (*pa)[i] = (int *) malloc( column * sizeof(int));     }     // note pa[i][j] same *(*(pa+i)+j)     count = 0;     (i = 0; <  row ; i++)         (j = 0; j < column; j++)             (*pa)[i][j] = ++count;  // or *(*(pa+i)+j) = ++count      (i = 0; <  row; i++)  {         (j = 0; j < column; j++)  {             printf("%d ", (*pa)[i][j]);         }         printf("\n");     } }  // how free 2 dimensional array  allocated memory using int ** ptr? void freearray( int *** pa, int row, int column) {  }  void test_array_allocation() {     int i, j;     int row = 3, column = 4;     int ** ptrarray;      allocarray( &ptrarray, row, column);      printf("test_array_allocation\n");     (i = 0; <  row; i++)  {         (j = 0; j < column; j++)  {             printf("%d ", (ptrarray)[i][j]);         }         printf("\n");     }     freearray(&ptrarray, row, column); // free allocated memory   }  int main(int argc, const char * argv[]) {     test_array_allocation();       return 0; } 

if doing it, can show me how this?

here's how implement this. i've never implemented 2d arrays in c before, fun bit of code write.

#include <stdio.h> #include <stdlib.h>  void* xmalloc(size_t n) {   void* p = malloc(n);   if (p == null)     {       printf("i handle errors!\n");       exit(exit_failure);     }   return p; }  int** alloc2darray(unsigned rows, unsigned cols) {   int** r = xmalloc(sizeof(int*) * rows);   (int = 0; < rows; i++)     r[i] = xmalloc(sizeof(int) * cols);   return r; }  void print2darray(int** a, unsigned rows, unsigned cols) {   (int = 0; < rows; i++)      {       (int j = 0; j < cols; j++)       printf("%4d", a[i][j]);       putchar('\n');     } }  void free2darray(int** x, unsigned rows) {   (int = 0; < rows; i++)     free(x[i]);   free(x); }  int main(void) {   int** x = alloc2darray(10, 14);    (int = 0; < 10; i++)     (int j = 0; j < 14; j++)       x[i][j] = i*j;    print2darray(x, 10, 14);   free2darray(x, 10);    return 0; } 

another tip might not aware of: can use valgrind on gnu/linux verify deallocated correctly:

==9322== heap summary: ==9322==     in use @ exit: 0 bytes in 0 blocks ==9322==   total heap usage: 11 allocs, 11 frees, 640 bytes allocated ==9322==  ==9322== heap blocks freed -- no leaks possible ==9322==  ==9322== counts of detected , suppressed errors, rerun with: -v ==9322== error summary: 0 errors 0 contexts (suppressed: 0 0)