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
Typedouble
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
Typeint
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
Typechar
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
Typestd::string
is a type for storing text strings. Strings are wrapped in double quotes "
.
std::string message = "good nite";std::string user = "codey";
bool
Typebool
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;