Difference between *pointervar and (*pointervar)

Question

On this page I've found the following code:

//insert a new node in front of the list
void push(struct Node** head, int node_data)
{
   /* 1. create and allocate node */
   struct Node* newNode = new Node;
 
   /* 2. assign data to node */
   newNode->data = node_data;
 
   /* 3. set next of new node as head */
   newNode->next = (*head);
 
   /* 4. move the head to point to the new node */
   (*head) = newNode;
}

Now I'd like to know why in the third line *head is in brackets? What is the difference between *head and (*head) ?

Answer 1

What is the difference between *head and (*head) ?

The brackets around *head are not needed. You can remove the brackets. It would have the effect as with brackets.

Usually, we explicitly put brackets around an expression, to circumvent/override operator precedence rules.

But in your example, there is no difference with or without brackets .

---

An example where the parenthesis are needed is shown below:

struct C
{
    void f(int);
};

int main() {
    auto ptr = &C::f;
    C c;
    (c.*ptr)(5); //PARENTHESIS NEEDED HERE ; this compiles
   // c.*ptr(5);   //this won't compile! because of operator precedence rules   
}