How do you declare a function that takes a pointer to an int and returns void?

• A. void update(int* p);
• B. int update(int* p);
• C. void* update(int* p);
• D. update(int* p);

Answer: (A)

The function’s return type and its parameter types determine how it can be used. To declare a function that takes a pointer to int and returns nothing, you specify void as the return type and int* as the parameter type. The typical form is: void update(int* p); Here, update is the function name, p is a parameter that receives the address of an int, and void means the function does not return a value. Inside the function, you could use *p to access or modify the int that the pointer points to.

Why this fits best: returning void means no value is produced, matching the requirement. The parameter type int* p explicitly states a pointer to int, which is what you want the function to receive. The other options either try to return a non-void type, return a void pointer, or omit a return type entirely, which would not meet the stated signature.