Hello World Program in C++

In this tutorial, we are going to code our first program: Hello World Program. This program is considered as the most common, even learning of any programming start with this program. In this program we are going to simply print “Hello World” on Console (Black Command Prompt Screen).

So let’s move ahead…

This is how a C++ Hello World Program looks like:

Now we will discuss all the statements one by one.

Consider,

As discussed in the previous article, firstly we include Header File which we will need in our program. “#include” is a Preprocessor Directive to include header files in our program. Preprocessor Directives are the line of code that starts with “#”, they are called so because they are executed by Preprocessor before the compilation of code (it’s obvious that we will need to include files before the process of compilation). “#include” is used to include files and “#define” is used to define Macros. There are some more Preprocessor Directives, but this two are most commonly used.

The name of the Header File to be included is provided within Angular Braces (like #include <iostream>) or within Double Quotes (like #include “iostream”).

The iostream header file provides us with stuff for Basic Input and Output. Iostream stands for the  input-output stream.

Consider,

Line No. 6, it defines our main function which is the entry point of our program.

The “int” is a data type which specifies what our main function is going to return at the end. It is called as the return type of function (here main function). We will learn more about them in the Function’s article.

“main” is the name of the function.

“main()”, this parenthesis specifies that main is a function.

Every function starts with an Opening Curly Brace “{“ and ends with a Closing Curly Brace “}”.

Consider,

Here we do our task of printing Hello World.

“std::cout” is the object of class ostream which is used to print on screen in C++, it is defined in “iostream” Header File. Since it belongs to the standard class of C++, we need to add “std::” in front of it.

“<<” is called as Insertion Operator, which insert the string “Hello World” inside cout object. The cout object is further connected to monitor via streams. It passes the string to monitor to print it.

“;” the semicolon ends all the statements in C++. It is used to indicate the end of a valid executable statement.

Consider,

Line No. 11: “return 0” statement returns 0 from main(). Operating System calls main() of each program, and in C++, main() must return an integer to Operating System and our return statement does the same.

The semicolon at end completes the return statement.

Consider,

“}” brace completes our main() and completes our Program too.

So now, let's Compile and Run our program to see results. The Output of Program Comes like:

So…Bingo, we have done with our Hello-World Program.

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