ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

AND? I Don't Understand: A Simple Explanation of AND logic function

Updated on January 25, 2015

Introduction

AND, in electronics or programming lingo, is a function that returns a 1 when all its inputs or conditions are 1. I know, you are probably saying “WHAT?? That made no sense!” Let’s start from the beginning. In electronics, logic gates are made from transistors and are the most basic part of an intelligent circuit. The function of a transistor is quite extensive; however, to make a logical circuit they are used to make 7 unique logic gates. These gates depend on the logical functions listed below:

  1. AND
  2. OR
  3. XOR
  4. NOT
  5. NAND
  6. NOR
  7. X-NOR

Understanding the lingo

Before we get into the details of the functions, let’s understand the lingo that I mentioned in the introduction. In electronics or programming, 1 means TRUE and 0 means FALSE. “I don’t get it”. Let’s try to understand using an example – When a light switch is switched to ON position, the light turns ON and when its switched to OFF position, the light turns OFF. “I knew that, how does that fit here?” ON means TRUE and OFF means FALSE. “So you are saying 1, TRUE and ON are all the same thing?” YES! And 0, FALSE and OFF are all the same. In fact, 1 can be said as TRUE, ON, HIGH or logical HIGH, it just means that a condition is TRUE. “What’s this condition now?” A condition is a situation, like in previous example, ON was the condition of the switch, which reflected the condition of the light. “Oh ok, so let me get this straight, when the switch is ON it means the condition of the switch is TRUE.” That’s exactly right!! And in return, the condition of the light changed to TRUE.

Learning by example

“OK I get that but how does this information explain the logical functions?” Let me tell you a small story. Steve and Marie have two children, Jack and Till. On a particular Sunday, Jack asked his father to take him to the zoo. Steve said, “We will only go to the zoo if Mum AND Jill want to go as well.” Jack said, “Mum wants to go but Jill doesn't.” “Maybe we can try to convince Jill as well” Steve said, “because, we will only go if Mum AND Jill agree.” In this little conversation, Steve kept saying “Mum AND Jill”, it means, that Mum AND Jill both have to say YES for them to go to the zoo. “Hang on hang on, so YES is the same as 1, TRUE and HIGH?” YES! The condition is that Mum AND Jill have to agree, so both conditions need to be TRUE in order for the family to go to the zoo. “I understand this, but give me another example.” OK, let me give you a scenario. Two light switches, switch1 and switch2, are wired in such a way that they both have to be ON in order for the Light to turn ON. What will be the condition of the Light if switch1 is ON and switch2 is OFF. “The Light will be OFF, obviously.” How did you figure that? “Well you said it yourself; switch1 and switch2 both have to be ON.” That’s it!

Technical stuff

“I think I am ready for the technical stuff. Hit me!” Alright then, the image below is of an AND gate and with it there is a table, that we call the Truth table in electronics lingo.

AND gate circuit symbol
AND gate circuit symbol
Input1
Logical function
Input2
Output
FALSE
AND
FALSE
FALSE
FALSE
AND
TRUE
FALSE
TRUE
AND
FALSE
FALSE
TRUE
AND
TRUE
TRUE
AND function Truth Table

Do you understand what this means? “I sort of understand it but why put options that won’t give a TRUE output?” That’s because for two inputs, we are putting all combinations or possibilities for input conditions. This means, that if we had three inputs, there would be eight combinations or possibilities for the input conditions. “Just out of curiosity, could I replace all FALSE in the truth table with 0, since they both mean the same thing, and TRUE with 1?” Bravo! That is exactly how the truth table is shown, let’s put it the right way. In fact, we don’t even need the Logical function column, since we already know what function we are talking about, however, for simplicity sake, I’ll leave it there.

Input1
Input2
Output
0
0
0
0
1
0
1
0
0
1
1
1
AND gate Truth Table

Ready for a challenge?

I believe you are ready for a challenge. “OK I’ll do my best.” This is a programming example but I have put it in words to keep things general to common programming languages. For RESULT of a student, GRADE is decided depending on the RESULT value. If RESULT >69 AND RESULT <80, the GRADE=Distinction. Keeping this condition in mind, if RESULT value was set to 65, would the GRADE value be Distinction? “Well, no because from your condition it seems you only want the GRADE to be Distinction if the RESULT value was between 69 and 80.” It’s actually 70 and 80, but besides that you are absolutely correct. You see “>” symbol means greater than, doesn't include 69. Technicality ;)

What's next?

This article is the first of a series of articles where we will explore other logical functions.

Comments

    0 of 8192 characters used
    Post Comment

    • profile imageAUTHOR

      husnen 

      3 years ago

      Thanks for the comment Ron. This is my first article and its really nice to have an encouraging feedback.

      The idea behind my article is to show the readers that many concepts of computer programming or electronics, or physics as a matter of fact, may be understood using simple real life examples and events.

    • RonElFran profile image

      Ronald E Franklin 

      3 years ago from Mechanicsburg, PA

      Interesting way of explaining the AND function that should make it easy for non-technical people to "get" it.

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, hubpages.com 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: https://hubpages.com/privacy-policy#gdpr

    Show Details
    Necessary
    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 googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    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)
    Marketing
    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.
    Statistics
    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)