C++ Info and Projects

C++ Info

General

C++ is a programming language, used for computers. C++ is created by a Bjarne Stroustrup, from denmark. C++ is a better version of C (C programming language). C++ have classes which C dosen't have.

Variables

Name	Description	Size*	Range*
char	Character or small integer.	1byte	signed: -128 to 127 unsigned: 0 to 255
short int (short)	Short Integer.	2bytes	signed: -32768 to 32767 unsigned: 0 to 65535
int	Integer.	4bytes	signed: -2147483648 to 2147483647 unsigned: 0 to 4294967295
long int (long)	Long integer.	4bytes	signed: -2147483648 to 2147483647 unsigned: 0 to 4294967295
bool	Boolean value. It can take one of two values: true or false.	1byte	true or false
float	Floating point number.	4bytes	+/- 3.4e +/- 38 (~7 digits)
double	Double precision floating point number.	8bytes	+/- 1.7e +/- 308 (~15 digits)
long double	Long double precision floating point number.	8bytes	+/- 1.7e +/- 308 (~15 digits)
wchar_t	Wide character.	2 or 4 bytes	1 wide character

Strings

Variables that can store non-numerical values that are longer than one single character are known as strings.

The C++ language library provides support for strings through the standard string class. This is not a fundamental type, but it behaves in a similar way as fundamental types do in its most basic usage.

A first difference with fundamental data types is that in order to declare and use objects (variables) of this type we need to include an additional header file in our source code: <string> and have access to the std namespace.

If, Else

If, Else

The if statement says that if that equals true then do something, if not then do something else. Like this:

#include <iostream>

#include "conio.h"

using namespace std;

int main() {
  // define two integers
  int x = 3;
  int y = 4;

//print out a message telling which is bigger
  if (x > y) {
    cout << "x is bigger than y" << endl;

_getch();
  }
  else {
    cout << "x is smaller than y" << endl;

_getch();
  }
}

Here we decleares that if X is bigger than why then print: X is bigger than Y, else if Y is bigger that x then print: X is smaller than y.


Projects
Hello World

#include <iostream>
#include "conio.h"
using namespace std;


void main(){
cout << "Hello World" << endl;
getch();
}

Hello World more lines

#include <iostream>
#include "conio.h"
using namespace std;


void main(){
cout << "Hello World" << endl;
cout << "Hello World" << endl;
cout << "Hello World" << endl;
cout << "Hello World" << endl;
cout << "Hello World" << endl;
getch();
}