ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

Three Simple C++ Programs With Detailed Explanations

Updated on July 15, 2016

Code 1

#include <iostream>
using namespace std;
int main() ]
cout << "This is a C++ Program" << endl;

From above, what we should all notice first is:


The above line called a header file or preprocessing directive.

Rules Governing Header Files In C++

  • All header files must start with the # character.
  • You cannot use a header file twice in a single program.

Don't relent by knowing how to use the iostream header alone, there are others you will use in the future.

If you use linux, you may find the those header files located in usr/include/c++/5.

Now we move on to:

using namespace std;

In this case, I suggest we should assume that this line is our printer that displays out our code with the functions cout and endl


This displays the body of our main functions

e.g cout << "I am a boy" << endl;

displays I am a boy without quotes.

In one word, it's function is just to break a line or jump to the next line.

Now back to our initial explanation. Without using namespace std; , we will have to type std::cout and std::endl everytime we need them. std in this case means standard.

using namespace std; is very important to make our program simple and neat.

int main()


This function specifies the the beginning of our program and we are declaring a function named main.


It specifies the end of our program. This function tells the complier to stop.

Open and Close curly braces are really so important.

Code 2: Variable Assignment

using namespace std;
int main() 
int x;
x = 10;
cout << x << endl;

The difference here is clear. This code stores an integer value and
then prints the value of the variable.

Declaring x is the number one step.

int x; else you will get an error from the compiler.


According to the program, x has a static value of 10 and to print this out, we use the cout function without columns:

cout << x << endl;

It then prints out 10.

Remember that all syntax in C++ must end with ; excluding header file and the main function.

Code 3: Getting Input From User

//This get a whole number from user
using namespace std;
int main() 
int x;
cout << "Enter a Number: << endl;
cin >> x ;
cout << "You entered " << x << endl;

//This get a string of text from user
using namespace std;
int main() 
string name;
cout << " What is your name?: << endl;
cin >> name;
cout << " Welcome " << name << endl;

cin is a function used to get input from users via Keyboard.

cin >> x; takes in the value of x the user provided, store it temporarily and then displays it out if it needed in the code.

The value of x won't just pop up, you have to use the cout function.

I'd love to hear you opinion about this, comment using a dummy cout function if you understands what I have explained so far. Also, try the simple quiz below. Meanwhile, if you missed my first C++ post, check it here:

What is the output of this code if the user inputs 20?

#include<iostream> //header file
using namespace std;
int main() 
int x,y; //declares variable x
cin >> x; // user input 20
cout <<" x + y " << x + y << endl; // displays the result

© 2016 Iyanu Victor


    0 of 8192 characters used
    Post Comment
    • profile image


      2 years ago

      I give you 5 star for this wonderful post


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)