Array Pointers

An array pointer stores the base address of an entire array. When incremented, it moves by the size of the whole array rather than a single element. This is particularly useful when working with multidimensional arrays.

int values[5] = {3,9,2,5,8};
int (*array_ptr)[5] = &values;

for(int i=0; i<5; i++) {
    printf("%d\t", (*array_ptr)[i]);
}

Pointer Arrays

A pointer array contains multiple pointer variables as its elements. Each element can point to different memory locaitons.

int a = 100, b = 200, c = 300;
int *ptr_list[3] = {&a, &b, &c};

for(int i=0; i<3; i++) {
    printf("%d ", *ptr_list[i]);
}

Pointer Functions

Pointer functions return memory addresses. The returned address must point to persistent memory (global, static, or heap-allocated).

int* create_value() {
    static int val = 42;
    return &val;
}

int main() {
    int *result = create_value();
    *result = 84;
    printf("%d", *create_value());
}

Fnuction Pointers

Function pointers store the entry address of functions, enabling callback mechanisms and dynamic function invocation.

int add(int x, int y) { return x+y; }
int sub(int x, int y) { return x-y; }

void calculate(int a, int b, int (*op)(int,int)) {
    printf("Result: %d\n", op(a,b));
}

int main() {
    calculate(10, 5, add);
    calculate(10, 5, sub);
}