C Pointer to Array

// Pointer to a fixed-size array of 5 integers
int (*pointer_name)[5];

// Pointer to a Variable Length Array of 'n' integers (C99)
int n = 5;
int (*vla_pointer_name)[n];

int *ptr_array[5]; // Array of 5 pointers to integers

int arr[5] = {10, 20, 30, 40, 50};

// Correct: &arr is of type 'int (*)[5]'
int (*ptr)[5] = &arr; 

// Incorrect: arr decays to 'int *', causing a type mismatch
// int (*ptr)[5] = arr; 

int arr[5];
int (*ptr)[5] = &arr;

// Assuming sizeof(int) is 4 bytes:
// The size of the pointed-to type is 5 * 4 = 20 bytes.
// If ptr holds address 0x1000:
ptr + 1; // Evaluates to 0x1000 + 20 bytes = 0x1014

int arr[5] = {10, 20, 30, 40, 50};
int (*ptr)[5] = &arr;

// 1. *ptr dereferences the pointer, yielding the array 'arr' (type int[5]).
// 2. The array 'arr' then decays into a pointer to its first element (type int *).
// 3. [2] accesses the element at index 2.
int val = (*ptr)[2]; // val is 30

int val = *(*ptr + 2); // Equivalent to (*ptr)[2]

int matrix[3][5];

// 'matrix' has type int[3][5].
// It decays to a pointer to its first element.
// The first element is an array of 5 integers (type int[5]).
// Therefore, the decayed type is 'int (*)[5]'.
int (*ptr)[5] = matrix; 

// These three function signatures are exactly equivalent:
void process_matrix(int (*matrix)[5]);
void process_matrix(int matrix[][5]);
void process_matrix(int matrix[3][5]); // The '3' is ignored by the compiler