`std::cin`

, which stands for “character input”, reads user input from the keyboard.

Here, the user can enter a number, press `enter`, and that number will get stored in `tip`

.

int tip = 0;std::cout << "Enter amount: ";std::cin >> tip;

A variable refers to a storage location in the computer’s memory that one can set aside to save, retrieve, and manipulate data.

// Declare a variableint score;// Initialize a variablescore = 0;

C++ supports different types of arithmetic operators that can perform common mathematical operations:

`+`

addition`-`

subtraction`*`

multiplication`/`

division`%`

modulo (yields the remainder)

int x = 0;x = 4 + 2; // x is now 6x = 4 - 2; // x is now 2x = 4 * 2; // x is now 8x = 4 / 2; // x is now 2x = 4 % 2; // x is now 0

`double`

Type`double`

is a type for storing floating point (decimal) numbers. Double variables typically require 8 bytes of memory space.

double price = 8.99;double pi = 3.14159;

`std::cout`

can output multiple values by chaining them using the output operator `<<`

.

Here, the output would be `I'm 28.`

int age = 28;std::cout << "I'm " << age << ".\n";

`int`

Type`int`

is a type for storing integer (whole) numbers. An integer typically requires 4 bytes of memory space and ranges from -2³¹ to 2³¹-1.

int year = 1991;int age = 28;

`char`

Type`char`

is a type for storing individual characters. Characters are wrapped in single quotes `'`

. Characters typically require 1 byte of memory space and range from -128 to 127.

char grade = 'A';char punctuation = '?';

`string`

Type`std::string`

is a type for storing text strings. Strings are wrapped in double quotes `"`

.

std::string message = "good nite";std::string user = "codey";

`bool`

Type`bool`

is a type for storing `true`

or `false`

boolean values. Booleans typically require 1 byte of memory space.

bool organ_donor = true;bool late_to_work = false;