Basics of C++

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Control IO

~ Page Overview ~

The Standard Library & Namespace

iostream

Outputting Data

Receiving Data

sstream

stringstream

~ Page Notes ~

~ The Standard Library & Namespaces ~

In Order to use any function/class from the Standard Library you must use it's namespace "std", followed by 2 semicolons and the function/class you wish to access.

~ #include ~

std::cout << var << " This is a chained output. \n";

Makes use of the insertion operator (<<). This inserts the following data to the stream that precedes it.

Line Breaks may be done either using "\n" or inserting the "endl" manipulator.

cout << "line.\n";

cout << "line." << std::endl;

std::cin >> int a >> double b;

Makes use of the extraction operator (>>), which is followed by the variable that will hold the extracted data.

The data is extracted as whatever type follows the extraction operator.

Only very simple programs should utilize "cin" for data extraction, since there is the possibility of no data being extracted and a variable left undefined, creating errors during said variables implementation. Instead use:

std::getline( cin, var ) ;

Note that data is extracted as a string.

When working with strings, cin recognizes white spaces, tabs, newlines etc. as the termination of value extraction.

~ #include ~

defines a type called stringstream

Can be used to turn strings into numerical values.

std::string mystr ("1204");

int myint;

std::stringstream(mystr) >> myint;

std::cout << myint+6;

1210

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FUNDAMENTAL TYPES

~ Page Overview ~

Type void

Integral's

Type char

Type int

Floating Point Numbers

Type float

Type double

Type long double

Boolean

Data Models

How 32 bit systems store variables

How 64 bit systems store variables

~ Page Notes ~

To determine the size of a type in bytes (8 bits) use "sizeof(var);"

~ Void ~

An empty set of values

An incomplete type

objects, arrays, & references are disallowed.

~ Integral's ~

Ranges based on Microsoft's default C++

You can double the size of any integral by preceding the type with the "unsigned" keyword, but in doing so the sign is always ignored.

( e.g. The range of a 16 bit, unsigned int is [0, +65,536] )

char

contains members of the basic execution character set. ( Microsoft C++ has a default of ASCII )

int

To size an integer precede w/ "__intb' where b = the bit size.

__int8

Range [-128 , + 127

__int16

Range [-32,768 , +32768]

Aka short, short int, signed short int

__int32

Range [-2,147,483,648 , +2,147,483,648]

Aka int, signed int

__int64

Range [-9,223,372,036,854,775,808 , +9,223,372,036,854,775,808]

Aka long, long int, signed long int

~ Floating Point ~

float

Range [3.4e +/-38] (for both +/-)

Smallest floating point #

4 bytes

double

Range [1.7e +/- 308] (for both +/-)

>= float

8 bytes

long double

>= double

In Microsoft's C++ double & long double have identical representation.

Considered a separate type from double.

~ Boolean ~

Holds either a true or false value

~ Data Models ~

32 bit systems

LP32 or 2/4/4 (int is 16-bit, long & pointers are 32 bits)

Win16 API

ILP32 or 4/4/4 (int, long & pointer are 32 bits)

Win32 API

Unix & Unix-like systems (Linux, Mac OS X)

64 bit systems

LLP64 or 4/4/8 (int & long are 32 bits, pointer is 64 bits)

Win64 API

LP64 or 4/8/8 (int is 32 bits, long & pointer are 64 bits)

Unix & Unix-like systems (Linux, Mac OS X)