UnderStanding Super Keyword Day 42 By Kishan

Ajouté : 2026-05-12

[00:00:00]can you please respond in the chat yes yes yes yes yes very very good evening guys very very good evening all right so let us start our session here today so guys before starting our session as always let us try to have a very very small and a quick recap of the concept which had covered in our skates class so guys yesterday yes we have started discussing about inheritance concept and I told you yes when you're speaking about inheritance acquiring the properties of one class into another class according the properties of one class into another class is known as inheritance it is also known as easy relationship and uh yes I told you in Java if you want to achieve inheritance we need to use either exchange keyword or implements keyword but as of now like up to yesterday I mean we have been discussing about exchange keyword regarding implements later I mean just wait for uh another two to three days after that we'll be discussing about implements keyword okay so yes we have seen what are the important key points which we need to remember in inheritance I told you there are four important key points are there four important key points so all those four important key points we already seen them like we can hold a we can hold a parent class object with a parent class reference and with the help of that reference we can call only parent class methods we can hold we can hold child class object with parent class reference and with the help of this reference we can call only parent class methods and we can hold we can hold child class object with Channel class reference and with the help of this reference we can call both parent and child class finally last one that is we cannot hold a parent class object with a child class reference so these are all the topics which are covered in our s test class and yesterday we have seen like a yes there are three types of inheritance are there like single events multi-love linear returns and hierarchical inheritance single inheritance in the sense single inheritance in the sense there will be only one level of inheritance single inheritance means there will be only one level of inheritance right so only one parent and one chain that's it not more than that when you are speaking about multi-level inheritance a child class object child class object should be able to access grandparent class method not only parent should be able to access grandparent class methods so that is actually multi-level inheritance and when you're speaking about hierarchical inheritance hierarchical inheritance means a single child class a single child class will have multiple parent classes I repeat a single child class can have multiple parent classes means if you are taking Class A you can inherit Class A and Class B you can inherit Class E and Class C you can inherit Class A in class B so multiple classes we can inherit so a single child class will be having multiple parent classes that is actually known as hierarchical inheritance that is actually known as hierarchical inheritance as simple as this asymplastics okay now right just a second guys just a second just a second right right so these are the concepts which we had covered in our ashtrays class ashtrays class so okay until you're asking sir Give an example for uh hierarchical inheritance okay okay guys please observe here this is Class A okay let me try to have a method void a method one like this okay system dot out or println system.out Dot printlr and here I am writing here sorry here I'm writing class EA method just let me try to write like this Class E method okay let me make this as public Pub LIC public and uh I want to inherit this class EA in class B can I do that in class B can I do that yes of course what I need to do extends Class A like that now here let me try to have my main method main method now inside my main method inside my main method just let me try to create an object to verb new class B like this child class object with the help of Cherry class object with the help of child class object I am trying to access with the help of with the help of child class object I am trying to access pay command tell me trying to access parent class method that's it pair and class method am I right right now just let me try to execute right click run as Java application see class a method okay just let me try to make it like this class a method okay just let me save it right click run as Java application like this now let me try to open let me try to open one more uh class here from another package let me go with another package sir am I supposed to use the same package or else other package guys you can you can use any package no issues no issues it's not mandatory that you need to use uh I mean you need to call from different packages it's your wish your wish any package okay now just let me do one thing I'll make this as Class B here like this and this is class X right just a second just a second right this is Class B this is class X okay now I'm trying to inherit not trying to I want to inherit I want to inherit Class A in class X tell me is it possible or not please tell me is it possible or not can I do that can I do that yes or no yes why not but what I need to do what I need to do yay yes first I need to import okay I am Purity import uh importer com dot okay import com dot pack one p a c k pack one daughter Class B class B like this be like this okay I'm importing it I'm importing it now as I have used import statement as I have used import statement now please observe here main method inside my main method let me try to create an object here inside my main method okay new class new class X dot new class x dot method one can I write like this guys uh sir actually we have imported Class B but what we need to import what do we need to import command guys you need to help me out here exactly we need to import Class A here Class A here right uh now even though I have imported Class A why I am getting an error here why I am getting an error here sir I did not provide inheritance sir okay extends extends Class A like this exchange class here like this now please observe here right click run as Java application I'm able to get my output like this now guys Class A we are able to inherit in class B and we are able to inherit in classics this is actually known as hierarchical inheritance am I clear with this guys Sharif this is hierarchical inheritance means a single class will be having multiple child classes multiple yes yes child classes add some glasses am I clear with this guys right right right Krishna I hope it's clear for uh I mean right now you need to import only you need to import only if both the classes are present in two different packages that's it buddy not more than that okay now Manoj you're asking me why don't we get output two times why we need to get output 2 times Manoj why we need to get output two times we are executing class X we are executing class X where is the main method main method is present in which class main method is present in class X we are executing this class X and inside this class X we are inheriting class EA and we are trying to call method one which is present in class A okay which method which class you are executing Mahesh sorry Manoj even though main method is present in class B are we executing Class B here or classics right right right right right I hope it's clear guys so this is actually hierarchical inheritance now now guys y Java does not support multiple inheritance will Java supports multiple inheritance will Java supports multiple inheritance the answer is no Java does not support multiple inheritance why okay guys we'll do one thing we'll do one thing for example guys please don't get confused between multiple inheritance and multi-level inheritance multiple inheritances different multi-level inheritance is different now please observe here please observe here let me remove this okay let me remove this now please observe here public void method one just think like this public void method one and here I am going with system dot out dot println Class B method system dot println Class B method okay now now let me do one thing I don't want to make you guys confused I am I will be using Class C which is from the same package so that it will be easy for you to understand okay right now guys please concentrate please concentrate here I am having Class A and Class B and Class C of course all the classes are present in the same package sir is it mandatory that all the classes should be present the same package no it is not at all mandatory just for our understanding purpose it will be like easy for you to understand I have taken like this am I clear with this uh guys can you please respond is it clear right right now now yes Java does not support multiple inheritance what if Java supports multiple inheritance what if Java supports multiple elements for example let us think that let us think that Java supports multiple inheritance okay now what is actually multiple inheritance a class should be able to inherit multiple classes class a comma Class B class a comma Class B okay are you getting me guys guys please tell me please tell me are you understanding me okay now I am trying to inherit multiple classes in a single class okay yeah obviously I will be getting an error why because Java does not support that but let us think that let us think that Java supports multiple narratives now let me try to have main method okay main method public Pub LIC public public static void main public static wide main string strange string array ergs arcs now here I'll be trying to create an object new class C new class c equal to cobj belongs to class C like this okay okay now for example for example for example right if I am trying to call c-o-b-j Dot method one which method will be getting executed which method will be getting executed class a method or Class B method which method how do you know that class a method will be getting executed how do you know that class B method will be getting executed so right now you are in a confusion right exactly the same thing will be happen for the compiler also it will be getting confused in order to call which method he does not know that so so this is the only reason multiple inheritance is not supported in Java am I clear with this guys is it clear right right right right right okay okay now now guys please keep an exciting just like a small point just like a small load point just like a small node point just like a small note point the point is node point just node Point note no T node Point number one Java does not support multiple inheritance due to ambiguity problem but multiple inheritance can be achieved in Java with the help of interfaces but multiple inheritance multiple names can be achieved achieved in Java with the help of interfaces so how to achieve that multiple inheritance with the help of interfaces when I am dealing with interfaces I'll let you know guys right now next Point important Point important point is Constructors does not participate in inheritance foreign Constructors to be precise Java Constructors does not participate in inheritance did you understand this point guys third point did you understand this third point please tell me right let us check let us check let us check let me try to have a program okay now here I want to have class B also please okay I'm having Class B Class A and Class B okay now guys please observe here please observe here let me try to have a method okay uh Word Method one like this avoid method uh guys for 5 to 10 minutes I need your complete concentration not more than that please please for five to ten minutes I need your complete concentration can you do that for me please please yes right right now please concentrate guys concentrate let me just try to have a method system dot dot println and here I am writing class EA method just simply class a method that's it now in class B I'm trying to have a method void method to void method two system dot out Dot println and here I am writing Class B method okay I want to take a Constructor in class A system.out.interland system.out.interland I'm just writing class EA E for Constructor class a default Constructor in the same manner I want to write a Constructor in class B also Class B Constructor and here I am writing class B default Constructor this class a default Constructor this is Class B default Constructor guys up to now did you understand the code up to now whatever the code which I have written everyone have understand this very good nothing just simply a method here a Constructor here a method here a Constructor here that's it not more than that okay now what I want to do you know I want to achieve inheritance tell me which keyword I need to write which keyword I need to write actions okay EST NDS extends uh stems come on tell me extends Class A okay let me go to my main method let me go to my main method now inside my main method I am trying to create an object okay new class B new class B I'm creating an object and let me try to have a reference b o b j belongs to class B like this okay Class B like this now b o b j dot method to B over here dot method okay I'm not even calling method one am I calling method one am I calling method one no I am not calling method one I am calling method two which is present in class B with the help of Class B object only can I call like this yeah of course I can call like this now can you please tell me what is my expected output what is my expected output please tell me go ahead go ahead go ahead eight time guys guys guys please please before giving me the output before giving me the output I request you please observe the program correctly here please before giving me the output please observe the program correctly and then give me the output guys I have written a Constructor here I have written a Constructor here come on guys I have written a Constructor right right right right right right so guys you are saying that I'll be getting I mean here what I'm doing I'm creating an object with the help of new keyword new keyword and I'm initializing that object with the help of a Constructor so first Constructor will be getting executed okay so Class B default Constructor after that class B method okay now before showing me the output like before showing you the output can you please read the third point for me slowly slowly slowly please slowly yes Constructors does not participate in inheritance okay now let me execute my program let me execute my program right click run as Java application what how class a default Constructor got executed class a default Constructor got executed did we created an object for Class A no will Constructors participate in inheritance no then how how class a default construct is getting called right right now guys please listen to me please listen to me in Java in Java you guys already know about this keyword and this Constructor call did you remember this keyword in this Constructor call this Constructor call is used to call what this Constructor call is used to call what this Constructor call come on guys seriously I'm seeing you I'm asking this is a keyword this is a Constructor call did you remember that uh now tell me this Constructor call is used to call present class Constructors am I right or wrong yes present class Constructors this keyword is used to call present class variables and methods just like this keyword and this Constructor call just like this keyword and this Constructor call in Java we are having a concept known as super keyword and super Constructor call what is this it is a keyword it is a keyword it is used to call parent class methods and variables are you understanding me guys super keyword is used to call parent class methods parent class methods and variables sir are you saying that are you saying that we can call sup or super dot method one like this yeah that is exactly I'm trying to say here guys super is a keyword which is used to call parent class methods are you understanding me here yes please please tell me please tell me yes exactly exactly okay what about this what about this Constructor yeah it is a Constructor call it is a Constructor call it is a Constructor called what is the use of this Constructor call it is used to call parent class ah can you please complete the sentence it is used to call come on guys please complete the sentence please complete the sentence it is used to call pair in class c o n s t r u c Taurus parent class Constructors it should be the it should be the ah what it should be the come on tell me it should be the first statement it should be the first statement statement inside a Constructor it should be the first statement inside a Constructor okay okay sir I understand super Constructor call is used to call the parent class Constructors okay but right now in this particular program we did not give any super Constructor call did we give any super Constructor call here no but how this Constructor got invoked because super Constructor call okay just let me try to write like this here I'm trying to write like a small uh Point kind of thing here just a second right all right Point number one Point number one super Constructor call is used to call the parent class Constructors super Constructor call means like this super Constructor call is used to call the parent class Constructors okay foreign call should be used only inside a Constructors used only super Constructor call super Constructor call should be used only inside a Constructors super Constructor call super Constructor call should be the first statement inside a Constructor should be the should be the first statement inside a Constructor Point number four Point number four in every Java Constructor by default compiler will automatically adds super Constructor call as its first statement in every Java Constructor by default compiler will by default by default compiler will automatically adds super Constructor call super Constructor call as its first statement do you understand guys did you understand right now right now even though we did not okay for example if we write super Constructor call like this then guys is it guys you need to help me out please if we write super Constructor call like this then this Constructor will be invoked am I right or wrong if we did not write also no problem if we did not write also no problem why because by default compiler will be adding us every Constructor with a super Constructor call for example let me try to write Class A like this and here I am making it as string s and I want to print s y s o I want to print yes I want to print yes ah now tell me guys now tell me I want to call my parameterizer Constructor with the help of the super Constructor call default Constructor will be executed or parameterized the Constructor will be getting executed default exactly exactly but I want to call my parameterizer Constructor can you please help me how I need to call it where I need to do it what I need to do it exactly exactly inside this super Constructor call we need to write let me go with Java is Joey's awesome I'm writing like this Java is awesome now which Constructor will be getting executed what is my output first what is my output guys if I execute my program if I execute my program first Java is awesome will be printed after that class B default Constructor after that class B method after that method one class a method please take this right click run as Java application Java is awesome class B default Constructor Class B method and class a method for example guys if I write like this can I write like this can I write like this what is the use of this come on tell me what is the use of this exactly Mukesh very good here very good Krishna that is good raw thought good Manoj yes that is good yeah we are calling which Constructor we are calling present class Constructor with the help of this Constructor call I'm right or wrong so right now if I execute my program First Class A Constructor I mean default Constructor after that Java is awesome after that class B default Constructor after that method Class B method and Class C method am I right or wrong tell me did you understand the concept guys did you understand the concept right right right right right that is good that is literally very good now guys please answer my question guys please answer me a question for example for example let me try to have Class B Class B and here I am writing uh int into some EA like this NTA like this okay now here system dot out dot println I am writing a Class B Class B p-a-r-a-m-e parameters Class B parameterizer Constructor plus a like this now my question is listen to my question correctly can I call can I call Class B parameterizer Constructor from class B default Constructor with the help of this Constructor call this Constructor call okay okay can I write like this okay this uh 10.

[00:37:42]can I write it like this I'm getting another why I am getting an error why I am getting an error it should be the first statement okay now why I am getting an error did you understand the problem here guys did you understand the problem here now answer my question can we use super Constructor call and this Constructor call both inside a Constructor no exactly exactly we cannot use we cannot use this Constructor call and super Constructor call both inside a Constructor we cannot use this Constructor call this Constructor call and super Constructor call both inside a Constructor you know the reason why because both should be the first statement so that is not possible am I right or wrong can we use this keyword and super keyword both inside a Constructor guys can we use this keyword and super keyword both inside a Constructor keyword keyword I'm asking keyword keyword guys keyword I can do that I can do this no problem keyword I can use keyword I can use but Constructor call I should not for example for example please observe here super dot method one okay let me try to have one more method void method three void method three and here system dot out dot println I'm just trying to write method three called called now can I write this dot method three Sno super keyword this keyword both I can use inside a Constructor but super Constructor call and this Constructor call I cannot use that I hope it's clear guys okay just let me try to write like this we can use we can use this and super keywords keywords both inside a Constructor but we cannot use Constructor calls okay I hope it's clear guys now just like this keyword Point number seven just like this keyword we cannot use super keyword also inside a static area am I clear with this guys just like this keyword we cannot use super keyword also inside a static area in the same manner exactly the same manner just like just like this Constructor call this Constructor call we cannot use super Constructor call super Constructor call also inside a static area I hope it's clear guys for everyone is it clear is it clear now now right okay just a second kalyani kalyani can you please unmute your mic once kalyani please unmute your mic One Summer you can unmute you can unmute please check please check please check yeah unmute unmute your mic I wanna I wanna speak with you please unmute yes can you hear my voice Amma can you hear my voice okay you are you are not audible telling you are not audible oh yes now it is audible now it is audible can you hear me yeah uh just now the sound came mama just know the sound came just know the sound came and went please check oh you had mute okay please check please check your mic once please unmute and please take your mic once you are unable to do that okay right uh guys I need someone to assist me to get the code it's okay it's okay no problem guys I need someone to help me to give me the output of this program can anyone please wants to help me you can message me in the chat I'll unmute you anyone anyone I'll just try to run my program with your help with your guys help I just want to write the output that's it you can and anyone anyone guys you can tell me uh please message me in the chat please message me in the chat please message me in the chat okay yeah Umesh that is fantastic buddy that is fantastic okay let me do one thing okay Umesh that is very good too much can you please unmute yes can you hear my voice Umesh yes sir fantastic buddy okay let us try to execute this code right now so Point number one point number one super Constructor call is used to call parent class Constructors is it clear right sir super keyword is used to call parent class method or parent class variables variables this Constructor call is used to call this Constructor call is used to call parent class present class president class sorry present class method Constructors Constructor sorry yeah present class Constructor this Constructor call is used to call the present class Constructor okay buddy let's go let us start analyzing our code okay let me go with notepad right now so Umesh you already know that every Java program execution starts from main method okay let us go with the main method now inside this main method inside this main method what we are doing we are trying to create an object object of a new keyword and we are initializing that object with the help of a constant structure which Constructor I'm actually I'm having two Constructors in my class which Constructor I am using non-parameters so from line number 28 our compiler will be directly coming to line number 14.

[00:46:37]yes sir now inside this Constructor inside this Constructor okay for example Umesh let us do one thing let us do one thing for example I want to write 50 here like this 50 50. okay now from line number 28 can you please tell me which line my compiler will be going I guess 22 sir 100 correct so what is even a 50 exactly now compiler will enter into this Constructor and inside this Constructor Umesh by default by default compiler will be providing us with a super Constructor Constructor right or wrong right sir so that super Constructor call is something like this right right sir so once we have created an object with the help of the parameterizer Constructor our compiler will be directly going to the default particles which is present in classic classic right sir so this should be our first Outpost output this should be our first output okay after that here there are no statements so directly our compiler will be coming back to line number 25 number 25 25 right so here Class B parameters Constructor and what is a value 50 50 okay just a minute a value is 50. why you will be getting your output like this the value is 50 okay so here all the statements got completed completed now we are calling method two method two okay let us go to Method two here uh inside this class B method method printed yes and with the help of what is this method a super uh keyword super keyword we are calling method exactly with the help of the super keyword we are trying to call method one which is present in so class a method method will be printed printed all right right so no statements are there so basically if you are trying to create an object with the help of this parameterizer Constructor we are expecting our output like this let us check right click run as Java application are we getting the same output buddy yes sir class a default Constructor Class B parameter is a constructive Class B method and of course class is a method so guys I hope it's clear for everyone is it clear for everyone yes uh please respond in the chart for me guys okay that is very good that is very good okay guys now let us try to go in one more manner one more manner okay Umesh are you ready yes sir okay we'll do one thing just right now let us go with default Constructor of Class B okay buddy sure sir yeah tell me from line number 29 where my compiler will be going line number 14 is fantastic line number 14. inside this line number 14 from line number 16 actually we are trying to call which Constructor classy Constructor I mean in class A there are two Constructors one is defaults are parameterized parameterized fantastic parameterizer Constructor of Class A what is this value uh Java is awesome let us check uh what is this value Java is awesome so this is s value that is s value is Java is awesome okay now inside this Constructor what is the use of this Constructor call buddy we are calling present class from classes exactly present class Constructor so from line number 15 our component will be going to which line line number nine sir that is hundred percent right line number nine line number nine and inside this we are having class called Constructor that should be our first output output class a default Constructor should be our first output uh after that are there any statements Left Behind no so from line number 11 our compiler will be coming back to line number 16 I mean yeah okay 15 after that the next statement is line number six yeah that is 100 right and yes well what is this value yeah is awesome B printed Java is awesome should be printed now are there any statements Left Behind no sir so directly or compile will be coming back to here why uh because we cannot use uh super and this Constructor in a present class Constructor that is very good that is very good we cannot use super Constructor call and this Constructor call both inside a Constructor why because both should be the first statement first if you are writing a super keyword this construct I mean Super Constructor call this Constructor call will be the second statement okay if you are trying to write this Constructor call as a first statement super Constructor call will be the second statement that is okay so there is the reason we had kept this in common okay after that system.out.printle and classes should be printed printed okay after that ah what is this uh Umesh what is this keyword super keyword method one I mean method one is present in which class uh class uh Acer yes obviously Class A in class A we are having this method that is class a method is there I mean we'll be getting that output class here method like this so here there are no statements are there so directly our company will be again coming back to here now in line number 20 what we are doing we are trying to call method three with this present in class b sir that is present class methods right or wrong right method three so method three called will be printed after that there are no statements here so directly our company will be coming back to main method and in service line number 30 method two to directly method two will be our company will be coming here Class B method will be printed Class B method will be printed and after that what we are doing here Umesh we are calling method one with the help of super keyword again what is the use of super keyword uh it is used to call uh present class uh present class sorry present uh super keyword is used to call method in uh parent class exactly parent class parent class exactly exactly so from line number eight we should be coming to line number five here and class a method will be printed class a method will be printed so here there are no statements let us come back here also all the statements got completed and our project like our program is done let us see your output right click run as Java application are we getting the same output class a default Constructor Java is awesome class B default Constructor class a method method three called Class B method class method thank you mesh thank you very much thank you so thank you guys I hope it's clear for everyone is it clear ready for a task ready for a task right do one thing first try this program first write this program please first write this program first write this program foreign foreign foreign wait for two minutes guys you've completed please inform me in the chat if complete please inform me in the chat like if you're not informing me I don't know please inform me in the chat right I hope the class C is complete for everyone please Class B Class B Class B appendicular first note on this class B M I'll show in the last okay foreign foreign uh guys I advise you to write the comments also please guys please inform if completed please inform if completed I'm waiting I'm waiting all right one more minute one more minute just one more minute right right I hope it's complete for everyone right right ready for the task ready for the task okay guys before going to the task before going to the task uh here I did not gave any parameter if I did not give any parameter this is my output please can you please note it down please can you please note it down please foreign now if I give a parameter if I give a parameter means something like 10.

[01:08:23]now this is my output this is my output if I give a parameter I hope it's careless for everyone foreign [Music] foreign task time please note down the program please note down the program for me please go ahead write down the program thank you shortcuts please use shortcuts it would be easy for your shortcuts please use shortcuts foreign oops foreign for everyone up to method for complete for everyone okay no please be fast be fast chandraman please be fast okay I hope it's completed take time guys please take time and try to get the output correctly don't go in a hurry buddy manner okay please okay this is the main method this is the main method that's it yeah guys I mean you need to wait here like I'm scrolling like everyone should write write this is the main method that's it not more than that right okay guys I hope you have written the program I hope you have written the program so please try to get the output for this program guys okay right show me that is very good uh Krishna are asking sir but we see that constructed participating inheritance Krishna constructory is not participating in inheritance we are calling the Constructor with the help of super Constructor call there is a difference please don't get confused with Krishna okay as super Constructor call is there Constructor is getting invoked okay that is the difference between invoking and calling please don't get confused right yes yes all right guys all right all right that's it that's it for today that's it for today so tomorrow we'll be trying to discuss about one more New Concept in oops features I hope you have enjoyed our today's session and uh guys yes uh I think uh yesterday did you see the Instagram ID which I have posted did you see an ID yes I believe you guys are already Following also so one thing is guys in that uh Instagram every day I'll try to upload a question every day simple question simple question I'll try to upload okay so please try to check whether you are able to uh like answer that question if you are getting that in the interview or not right so simple one one one one one question daily makes a bulk of cushions like that I'll try to upload it okay and if possible please try to give the give your own answer in the comment section also so that other students also will be able to see that okay all right all right so your pick is not there in Instagram okay you want uh you want me to upload my pick there insta what do you say guys okay fine then consider it's done consider it's done okay I'll upload it I'll upload it right okay guys thank you guys thank you for uh listening thank you for listening and uh I understand I understand we'll be trying to continue our sessions Again by uh tomorrow tomorrow there is a class tomorrow there is a class there is a class tomorrow okay uh tomorrow is not a holiday guys uh if it is holiday tomorrow anyways like after I did not got any information after I did not got any information if I got any information I'll try to upload it in our Google Classroom okay so as of now tomorrow is not holiday as of now am I clear with this right right guys okay guys thank you thank you for listening have a great day and uh if tomorrow is holiday is there happy Holi if tomorrow holiday is not there also happy Holi right guys right right thank you guys thank you uh bhargavi Instagram link uh I think Instagram link I have already given in the like uh Google Classroom this is a scam tally this is the scan or else you go with this ID this is better this is better okay and you will be seeing nearly some 700 uh plus followers will be there and you can get with that okay yeah guys happy Holi happy Holi to you also in advance thank you guys thank you for listening thank you bye