Pointer declaration 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. It 'points' to the location where data is stored.

beginner

How do you declare a pointer to an integer in C++?

You declare it using the syntax: int* ptr; Here, ptr is a pointer to an integer.

beginner

What does the asterisk (*) mean in a pointer declaration?

The asterisk (*) indicates that the variable is a pointer type, meaning it holds the address of a variable of the specified type.

beginner

Explain the difference between int* ptr; and int *ptr;.

Both are the same. The position of the asterisk (*) does not change the meaning. It just shows ptr is a pointer to an int.

intermediate

What happens if you declare a pointer but do not initialize it?

The pointer will contain a garbage (random) address. Using it without initialization can cause errors or crashes.

Which of the following declares a pointer to a float?

A float* ptr;

B float ptr*;

C ptr* float;

D float &ptr;

The correct syntax is float* ptr; which declares ptr as a pointer to a float.

What does the pointer variable store?

A The size of a variable

B The value of another variable

C The memory address of another variable

D The type of a variable

Pointers store the memory address of another variable, not the value itself.

How do you declare a pointer to an integer named p?

A int p*;

B int &p;

C int p;

D int* p;

The correct declaration is int* p; which means p is a pointer to an int.

What is the value of an uninitialized pointer?

A Random garbage address

B NULL

C The address of the pointer itself

D 0

An uninitialized pointer contains a random garbage address and should not be used before initialization.

Which symbol is used to declare a pointer?

A &

B *

C #

D $

The asterisk (*) symbol is used to declare a pointer variable.

Describe how to declare a pointer to a variable in C++ and explain what it stores.

Think about how you tell the computer to remember where something is stored.

What risks are there if you use a pointer without initializing it first?

Consider what happens if you try to use a random address.