How to evaluate double pointers in c?

Question

I am learning c, and I am quite confused about this double pointer question.

int x = 44;
int *p = &x;
int **t = &p;

bool a = (*t = &x);

I need to tell whether a will be true or false, and the correct answer is true. My thoughts were that t points to the address of p, and p points to the address of x. I know if you put **t, it should point to the address of x, but I thought if you just put *t it should point to the address of p. Can anyone explain?

Answer 1

int x = 44;

Declares integer variable x, which stores value of 44.

int *p = &x;

Declares integer pointer variable called p, p now stores the address of x.

int **t = &p;

Declares pointer to pointer of type int called t, t stores the address of p. (Pointers have addresses too)

bool a = (*t = &x);

In C;

'*' = Extracts the value from an address (Dereference)

'&' = Gives address of variable (Reference)

Since t is a pointer to the value stored in p. *t will be the value stored in p, which is the address of x. (We figured this out in the second line)

On the other hand since the & is used on variable x. This will extract the address of x.

Therefore *t == &x, which sets the boolean value a to true.