Advanced Pointers, Multidimensional Arrays, Function Pointers, and Dynamic Memory

Dynamic Memory Allocation

#include <stdlib.h>

int *arr = malloc(5 * sizeof(int));
if (arr == NULL) {
    return 1;
}

for (int i = 0; i < 5; i++) {
    arr[i] = i * 10;
}

free(arr);

malloc, calloc, realloc, and free are central to many C programs. Memory leaks and invalid access bugs often come from incorrect use of these functions.

Multidimensional Arrays

int matrix[2][3] = {
    {1, 2, 3},
    {4, 5, 6}
};

Multidimensional arrays are useful for grids, matrices, board problems, image-like data, and table-based computation.

Function Pointers

int add(int a, int b) {
    return a + b;
}

int (*operation)(int, int) = add;
printf("%d\n", operation(2, 3));

Function pointers support callbacks, dispatch tables, plugins, menu handlers, and more advanced system-level design.

Double Pointers

A double pointer stores the address of another pointer. It is often used when a function needs to modify a pointer owned by the caller, or when working with arrays of strings and complex dynamically allocated structures.

Memory Safety Habits

• Always check allocation results.
• Free exactly what you allocate.
• Do not use memory after free.
• Initialize pointers clearly.
• Document ownership expectations.

Real-World Usage Snapshot

Dynamic memory and advanced pointer handling are essential for parsers, protocol handlers, data structures, operating system utilities, and high-performance native libraries. This is one of the core reasons C remains both powerful and demanding.