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Your first program

C++ is an object oriented programming language based on C language. C++ was invented by Bjarne Stroustrup in the year 1979.​

Initially Stroustrup called the language as C with classes because it had object oriented features. C++ is a compiled language and is oriented towards systems programming and embedded systems.​

Instead of talking about history of C++, let us write our first C++ program.


#include<iostream>
using namespace std;
int main()
{
    cout<<"Hello world"<<endl;
    return 0;
}

main function​

C++ program must have a main function - which indicates the starting point of the program. Execution of the program begins with main function.​

int main()

- A function can return a value. If it does not return a value, the function is specified as void function. The type of the return value is specified before the function name. In this case main function returns an integer value - it returns 0 to indicate success.

Please remember that in C language, if return type of function is not specified, it defaults to int. But in C++, this will cause a compilation error.

cout object

In C++, the input and output are performed using objects cin and count (console in and console out).

cout uses the overloaded operator << (insertion operator) to display values. Do not confuse this operator with left shift operator.

cout<<10; cout<<m<<n;

endl

endl is a constant which stands for '\n' character. It displays a newline character.
namespace std

As the C++ programs get really complicated, related code and classes are placed in different groups called namespaces. All the standard library objects are available in a  namespace called std. That is the reason you need to import the namespace std.

iostream or iostream.h?

cin, cout, endl and other i/o classes and variables are declared in a file called iostream. That is the reason we need to include this file.

Some older compilers may use iostream.h. But most compilers use the header files without .h extension.

Compiling the program

There are many C++ compilers available. The preferred one is always gnu compiler g++.

g++ myprogram.cpp

Like C program, the C++ compiler creates an executable file with the name a.out by default.

But if you just want to test your programs online, you can use online compilers like ideaone
 
 First rule of learning 
I realized something when I was reading about python basic. In order to learn a new language, you need to have at least two windows. One in which you read and the other in which you run the code.\

So download and install your favorite IDE today or if you work on linux based system install g++ compiler. And start running the programs along with this blog. 

Happy learning!! 
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