Structure of C++ program

For making the c++ program you need to know how to write the code means what is the syntax, what is the structure.

1 . Header

2 . using namespace std;

3 . main function

{

  Code here

  return 0;

}

Now we make program that will give the output hello world :

#include<iostream>

using name std;

int main()

{

    cout<<”Hello World”;

    return 0;

}

Finish, when you compile this program the output will be Hello World.

Now we talk about every step in detail.

1.  Header :

C++ defines several header, which contain information that is either necessary or useful to your program. For this program, the header <iostream> is needed.

C++ input/output stream are primarily defined by <iostream>

2.  The line using namespace std; :

Tells the compiler to use the std namespace. Namespaces are a relatively recent addition to C++.

std is the standard namespace. cout, cin and a lot of other things are defined in it. This means that one way to call them is by using std::cout and std::cin.

3.  The line int main() :

Is the main function where program execution begins.

4.  The next line cout << "Hello World"; :

Causes the message "Hello World" to be displayed on the screen.

cout is use for to display something on the screen.

Syntax of cout is cout<<”message”;

5.  The next line return 0; :

Terminates main( ) function and causes it to return the value 0 to the calling process. In other words we can say that the execution of program will be stop.

In C++, the semicolon is a statement terminator. That is, each individual statement must be ended with a semicolon. It indicates the end of one logical entity.