Understanding Arrays, Pointers, Operators, and Friends in C++

Kristoffer Hebert
Nov 3, 2018 · 2 min read

Object Oriented design in C++ with Kristoffer Hebert


Arrays are a fixed length list of indexes paired with values. Pointers are the memory addresses of variables. Operators tell the C++ compiler to manipulate values in a specific way. Class Friends have access to private and protected attributes of other Classes.

What are Arrays

In C++, Arrays are a collection of index value pairs with a fixed length. You access values by selecting a valid index. Indexes in C++ Arrays begin at zero.

Array Examples

string groceryList = [5];
groceryList[0] = “Tomatoes”;
// Another way to intialize Arrays
string groceryList[] = { "Tomatoes", "Potatoes", "Carrots" };
// This errors out, because index is out of bounds of Array
string groceryList[2] = {};
cout << groceryList[4] << endl;

What are Pointers

A Pointer is an operator and variable that contains the address of another variable value stored in memory. It’s like a shortcut on your computer desktop that points to a file located elsewhere.

Pointer Examples

string message = “Tacos are delicious”;// * operator creates a shortcut to the value
string *shortcut;
// & operator gets the memory location of a variable
shortcut = &message;

// Returns memory address of 0x738d1e8a2370
cout << shortcut << endl;
// Returns Tacos are delicious
cout << *shortcut << endl;

What are Operators

Operators are symbols that tell the C++ compiler to perform specific manipulations on a value. There are various types of operators, such as Arithmetic, Logical, Relational, and Assignment. This is not an exhaustive list, but you can look them up on cppreference.com

Examples of Operators

+ Addition
- Subtraction
* Multiply
/ Divide

! Inverse of a boolean
|| Use first true value left to right
&& If both are true turn true

== Means equal to
!= Means does not equal
> Greater Than
< Less Than

= Assign the value to
+= Add value and assign that value to
*= Times the value and assign that value to
/= Divide the value and assign that value to

What are Friends

Friends in C++ are Classes that have access to private and protected attributes of other Classes.

Friend Syntax

class PersonOne {
friend class PersonTwo;

C++ Friend Examples

Key Takeaways

Friend Classes means another Class has access to it’s private and protected attributes. An Array is a fixed length collection of index value pairs. A Pointer is a variable that contains the memory address of another variable. Operators tell the C++ compiler to manipulate values in a specific way.

Kristoffer Hebert

Written by

I am working toward a simpler, more meaningful world. kristofferhebert.com

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