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This tutorial series will help you to get started in C++ to develop system applications.
/*
* File: main.cpp
* Author: Nano
* Just click image to copy & paste
*/
#include <iostream>
int main() {
std::cout<<"This is my first c++ Program.";
std::cout<<std::endl<<"and its very easy";
}
$ gcc -v/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 4:09 PM
*/
#include <iostream>
int main() {
std::cout<<"This is my first c++ Program.";
std::cout<<std::endl<<"and its very easy";
}
| /* Comments */ | Comments are a way of explaining what makes a program. Comments are ignored by the compiler and used by others to understand the code. |
| #include<iostream> | is a preprocessor directive. It tells the preprocessor to include the contents of iostream header file in the program before compilation. This file is required for input output statements. |
| int/void main() | int/void is a return value, which will be explained in a while. |
| main() | The main() is the main function where program execution begins. Every C++ program should contain only one main function. |
| Braces | Two curly brackets “{…}” are used to group all statements together. |
/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 4:09 PM
*/
#include <iostream>
using namespace std;
int main() {
cout<<"This is my first c++ Program.";
cout<<endl<<"and its very easy";
}| return 0 | At the end of the main function returns value 0. |
Manipulators are operators used in C++ for formatting output. The data is manipulated by the programmer’s choice of display.
setw(x)/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 12:58 PM
*/
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
float basic, ta,da,gs;
basic=10000; ta=800; da=5000;
gs=basic+ta+da;
cout<<setw(10)<<"Basic"<<setw(10)<<basic<<endl
<<setw(10)<<"TA"<<setw(10)<<ta<<endl
<<setw(10)<<"DA"<<setw(10)<<da<<endl
<<setw(10)<<"GS"<<setw(10)<<gs<<endl;
return 0;
}| Basic | 10000 |
| TA | 800 |
| DA | 5000 |
| GS | 6800 |
/*
* File: main.cpp
* Author: Gautam
* Created on October 16, 2011, 12:58 PM
*/
#include <iostream>
#include <iomanip>
using namespace std;
int main() {
cout << setw(20) << setfill('*') << "w3schools.in" << setw(20) << setfill('*')<<"Test"<< endl;
}| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| char | Any single character. It may include a letter, a digit, a punctuation mark, or a space. | 1 byte | -128 to 127 or 0 to 255 |
| signed char | Signed character. | 1 byte | -128 to 127 |
| unsigned char | Unsigned character. | 1 byte | 0 to 255 |
| wchar_t | Wide character. | 2 or 4 bytes | 1 wide character |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| int | Integer. | 4 bytes | -2147483648 to 2147483647 |
| signed int | Signed integer. Values may be negative, positive, or zero. | 4 bytes | -2147483648 to 2147483647 |
| unsigned int | Unsigned integer. Values are always positive or zero. Never negative. | 4 bytes | 0 to 4294967295 |
| short | Short integer. | 2 bytes | -32768 to 32767 |
| signed short | Signed short integer. Values may be negative, positive, or zero. | 2 bytes | -32768 to 32767 |
| unsigned short | Unsigned short integer. Values are always positive or zero. Never negative. | 2 bytes | 0 to 65535 |
| long | Long integer. | 4 bytes | -2147483648 to 2147483647 |
| signed long | Signed long integer. Values may be negative, positive, or zero. | 4 bytes | -2147483648 to 2147483647 |
| unsigned long | Unsigned long integer. Values are always positive or zero. Never negative. | 4 bytes | 0 to 4294967295 |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| float | Floating point number. There is no fixed number of digits before or after the decimal point. | 4 bytes | +/- 3.4e +/- 38 (~7 digits) |
| double | Double precision floating point number. More accurate compared to float. | 8 bytes | +/- 1.7e +/- 308 (~15 digits) |
| long double | Long double precision floating point number. | 8 bytes | +/- 1.7e +/- 308 (~15 digits) |
| Data Type (Keywords) | Description | Size | Typical Range |
|---|---|---|---|
| bool | Boolean value. It can only take one of two values: true or false. | 1 byte | true or false |
#include <iostream>
using namespace std;
int main()
{
cout << "Size of char is " << sizeof(char) << endl;
cout << "Size of int is " << sizeof(int) << endl;
cout << "Size of float is " << sizeof(float) << endl;
cout << "Size of short int is " << sizeof(short int) << endl;
cout << "Size of long int is " << sizeof(long int) << endl;
cout << "Size of double is " << sizeof(double) << endl;
cout << "Size of wchar_t is " << sizeof(wchar_t) << endl;
return 0;
}enum enum-name {list of names}var-list;enum mca(software, internet, seo);typedef [data_type] synonym;typedef [data_type] new_data_type;typedef int integer;
integer rollno;type variable_name;type variable_name, variable_name, variable_name;/* variable definition and initialization */
int width, height=5;
char letter='A';
float age, area;
double d;
/* actual initialization */
width = 10;
age = 26.5;| asm | else | new | this |
| auto | enum | operator | throw |
| bool | explicit | private | true |
| break | export | protected | try |
| case | extern | public | typedef |
| catch | false | register | typeid |
| char | float | reinterpret_cast | typename |
| class | for | return | union |
| const | friend | short | unsigned |
| const_cast | goto | signed | using |
| continue | if | sizeof | virtual |
| default | inline | static | void |
| delete | int | static_cast | volatile |
| do | long | struct | wchar_t |
| double | mutable | switch | while |
| dynamic_cast | namespace | template |
| And | bitor | not_eq | xor |
| and_eq | compl | or | xor_eq |
| bitand | not | or_eq |
Class class_name
{
Data Members;
Methods;
}class A
{
public:
double length; // Length of a box
double breadth; // Breadth of a box
double height; // Height of a box
}Class A
{
int i; // i is a data member of class A
int j; // j is a data member of class A
int i; // Error redefinition of i
}Class A
{
int i;
int j;
void f (int, int);
int g();
}#include <iostream>
using namespace std;
class Box
{
public:
double length; // Length of a box
double breadth; // Breadth of a box
double height; // Height of a box
}
int main( )
{
Box Box1; // Declare Box1 of type Box
Box Box2; // Declare Box2 of type Box
double volume = 0.0; // Store the volume of a box here
// box 1 specification
Box1.height = 4.0;
Box1.length = 6.0;
Box1.breadth = 3.0;
// box 2 specification
Box2.height = 10.0;
Box2.length = 12.0;
Box2.breadth = 12.0;
// volume of box 1
volume = Box1.height * Box1.length * Box1.breadth;
cout << "Volume of Box1 : " << volume <<endl;
// volume of box 2
volume = Box2.height * Box2.length * Box2.breadth;
cout << "Volume of Box2 : " << volume <<endl;
return 0;
}#include<iostream>
using namespace std;
class stud
{
public:
char name[30],clas[10];
int rol,age;
float per;
void enter()
{
cout<<"\n Enter Student Name, Age, Roll number"; cin>>name>>age>>rol;
cout<<"\n Enter Student Class and percentage in previous class"; cin>>clas>>per;
}
void display()
{
cout<<"\n Age\tName\tR.No.\tClass\t%ge";
cout<<"\n"<<age<<"\t"<<name<<"\t"<<rol<<"\t"<<clas<<"\t"<<per<<"%";
}
}
int main()
{
class stud s;
s.enter();
s.display();
cin.get(); //use this to wait for a keypress
} 
| Base class visibility | Derived class visibility | ||
| Public derivation | Private derivation | Protected derivation | |
| Private | Not inherited | Not inherited | Not inherited |
| Protected | Protected | Private | Protected |
| Public | Public | Private | Protected |
/* C++ program to demonstrate the working of friend function.*/
#include <iostream>
using namespace std;
class Distance {
private:
int meter;
public:
Distance(): meter(0){ }
friend int func(Distance); //friend function
};
int func(Distance d){
//function definition
d.meter=10; //accessing private data from non-member function
return d.meter;
}
int main(){ Distance D;
cout<<"Distace: "<<func(D);
system("pause");
return 0;
}#include<iostream>
using namespace std;
int main()
{
int i,j,k,space=10; // to print the pyramid in center, you can also increase the # of spaces
for (int i=0;i<=5;i++)
{
for (int k=0;k<space;k++)
{
cout<<" ";
}
for (int j=0;j<2*i-1;j++)
{
cout<<"*";
}
space--;
cout<<endl;
}
cin.get(); /*use this to wait for a keypress*/
} 
*
***
*****
*******
*********
#include<iostream>
#include<cctype>
using namespace std;
int main(){
int n,i=1,sum=0;
cout << "Enter a number: ";
cin >> n;
while(i<n){
if(n%i==0)
sum=sum+i;
i++;
}
if(sum==n)
cout << i << " is a perfect number\n";
else
cout << i << " is not a perfect number\n";
system("pause");
return 0;
}#include<iostream>
using namespace std;
int main(){
int x,y,sum;
float average;
cout << "Enter 2 integers : " << endl;
cin>>x>>y;
sum=x+y;
average=sum/2;
cout << "The sum of " << x << " and " << y << " is " << sum << "." << endl;
cout << "The average of " << x << " and " << y << " is " << average << "." << endl;
system("pause");
}#include<iostream>
#include<math.h> //sqrt function used
using namespace std;
int main(){
// Variable Declaration
int n;
// Get Input Value
cout<<"Enter the Number : ";
cin>>n;
cout <<"List Of Prime Numbers Below "<<n<<endl;
//for Loop Block For Find Prime Number
for (int i=2; i<n; i++)
for (int j=2; j*j<=i; j++)
{
if (i % j == 0)
break;
else if (j+1 > sqrt(i)) {
cout << i << endl;
}
}
// Wait For Output Screen
system("pause");
return 0;
}#include<iostream>
#include<iomanip>
using namespace std;
int main (){
int first, second;
cout << "Please enter two integers." << endl;
cout << "First" << setw (3) << ": ";
cin >> first;
cout << "Second" << setw (2) << ": ";
cin >> second;
string message = first > second ? "first is greater than second" : "first is less than or equal to second";
cout << message << endl;
system("pause");
return 0;
}string message = first > second ? "first is greater than second" :
first < second ? "first is less than second" : "first and second are equal";