Pointer and variable relationship in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a pointer in C++?

A pointer is a variable that stores the memory address of another variable.

beginner

How do you declare a pointer to an integer variable?

You declare it using the syntax: int* ptr; where ptr is the pointer variable.

beginner

What does the * operator do when used with a pointer?

It dereferences the pointer, meaning it accesses the value stored at the memory address the pointer holds.

intermediate

Explain the relationship between a pointer and the variable it points to.

A pointer holds the address of a variable. Changing the value through the pointer changes the original variable's value because they refer to the same memory location.

intermediate

What happens if you change the pointer's value itself?

Changing the pointer's value changes the memory address it points to, so it will point to a different variable or memory location.

What does the following code print?<br>

int x = 10;<br>int* p = &x;<br>std::cout << *p;

A Garbage value

B Address of x

C 10

D Compilation error

The pointer p stores the address of x. Using *p accesses the value of x, which is 10.

Which operator is used to get the address of a variable?

A &

B *

C ->

D %

The & operator returns the memory address of a variable.

If int* p; is uninitialized, what happens if you try to dereference it?

A It prints 0

B It causes undefined behavior (likely crash)

C It prints the address stored in p

D It compiles but does nothing

Dereferencing an uninitialized pointer leads to undefined behavior and can crash the program.

What does the pointer store?

A A memory address

B A value

C A variable name

D A data type

Pointers store memory addresses of variables.

How do you change the value of a variable using a pointer?

A You cannot change variable value through pointer

B Change the pointer variable itself

C Use the & operator on the pointer

D Use the * operator to assign a new value

Using *pointer = new_value changes the value at the memory address the pointer points to.

Explain in your own words how a pointer relates to the variable it points to.

Think about how a pointer is like a remote control to a TV.

Describe what happens when you change the pointer's value versus when you change the value it points to.

Consider the pointer as an address label and the variable as the house at that address.