Let us look at a simple code that would print the words Hello World.
#include <iostream>
using namespace std;
// main() is where program execution begins.
int main()
{
cout << “Hello World”; // prints Hello World
return 0;
}
Let us look at the various parts of the above program:
1. The C++ language defines several headers, which contain information that is either necessary or useful to your program. For this program, the header <iostream> is needed.
2. The line using namespace std; tells the compiler to use the std namespace. Namespaces are a relatively recent addition to C++.
3. The next line ‘// main() is where program execution begins.’ is a single-line comment available in C++. Single-line comments begin with // and stop at the end of the line.
4. The line int main() is the main function where program execution begins.
5. The next line cout << “This is my first C++ program.”; causes the message “This is my first C++ program” to be displayed on the screen.
6. The next line return 0; terminates main() function and causes it to return the value 0 to the calling process.

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