12th May 2026 - Core Java Demo Session 5

追加: 2026-05-27

[00:00:34]right guys.

[00:00:50]Okay. So last lecture I had taken it online as okay I was not well and sometimes this might happen in between especially for the offline students that I might go online and take the classes as well right it might happen so you need to be little prepared about it okay but however I assume that Yesterday's class the offline students were clear about it. Yeah. Did you all understand the class? Was there any problem in terms of the understanding part in the live class?

[00:01:35]You're able to follow. Now this might happen that at times when I'm not coming to classroom so that's a backup solution. I've kept it and I would be taking the class online. Is this clear?

[00:01:49]The second thing is there are few important announcements which I will be doing it little later but today we are going to start with installation of the softares.

[00:02:04]So let us try to understand okay in order to install the required softares what all things we need to do.

[00:02:15]Now the first thing you will have to get JDK because after that I'll teach you some basic debugging steps. So you're going to go online and type download JDK.

[00:02:31]And when you click here you might see that there are different versions of JDK that is available here. Now suppose you want to install JDK 26 anything above 17 17 and above of Java that is okay we can use that today because when you're learning spring boot without 17 version and above spring boot will not work.

[00:03:04]Minimum version minimum version of spring boot required is 17.

[00:03:12]But till Java 21 version we are going to discuss because JDK version 21 lot of changes related to data structures concept was done.

[00:03:29]The major changes to your data structures in Java happen to be in JDK 21.

[00:03:36]So you can either download 21 26 whatsoever but click on Windows and you see this MSI installer just click on this link.

[00:03:52]Okay, just click on it and wait for the download to happen.

[00:03:58]Now once this has been downloaded the next thing you'll have to just doubleclick on the file and start your installation like this. You go here doubleclick on the file and then after you click on run and then click on next next and then finish. Okay. So this is simple steps what you need to follow and install JDK first. Now what is this JDK?

[00:04:34]Why this is required? What is JRE JDK?

[00:04:38]We'll all talk about this little later.

[00:04:41]Our today's focus is firstly install the required software IDE and then after you can start coding. So let's click on yes.

[00:04:54]Okay. Let's click on what? Yes.

[00:05:04]Okay. Now click on close. Now to verify that the installation is done, you just go to C drive and you will see here a folder called as program files. You click on it and observe there is a Java folder created and in that 26 version that installed that got installed. Now I have lot of versions you can see that in my system I've installed 17 21 22 23 4 25 26 any number of versions you can install together.

[00:05:43]Don't think that JDK 21 is there then 17 cannot be there. All the versions of JDK that you want you can install that in your local computer.

[00:05:58]This is the first thing. Now once this has been done the next step you will all have to go online here and download Eclipse sir during our course I will definitely teach you different different IDE specially our complete project work will happen on IntelliJ which you can see this here right so this is where the complete project work I would be doing it fine but for now to begin with just follow what I am telling you start with Eclipse okay now people might have different different mindset some fresher might tell I will use VS code somebody will say I will use intelligj some other fellow something else see ultimately right now we have to learn Java and ID learning is not difficult one or two classes you can start understanding how to use IDE the core crux the core part here is your Java programming language that's the core part so now what I will do I will just go here to Eclipse downloads click on this and then after you need to download click on this download button x8 8664.

[00:07:30]This is what you need to download. Is this clear everyone? Now see this is a kind of big software. So have patience.

[00:07:40]Okay, have patience. So however I have a decent internet speed. So this is little fast but in your case it might go little slow but ensure there is no interruptions while downloading it. The file should not get corrupted. Now once this has been downloaded the very next thing guys what I'm going to do here is this. Let's wait with patience for it to completely get downloaded.

[00:08:10]That's done. Now all you need to do is just doubleclick on this file and click on run. This already been installed. That's okay. I'll still click on yes. And then what I will do is I will continue with the installation as you see here. Click on next. Then next and then finish.

[00:08:36]So this is how you guys are going to install. Okay. Basically Eclipse.

[00:08:44]Are you understanding now? So what we downloaded is Eclipse.

[00:08:48]Okay. Now once this has been installed you close this and you can now launch Eclipse.

[00:08:57]So you will see this icon here. I have lot of icons on the desktop. Lot of icons are there on the desktop. The I can install multiple Eclipse. I have installed already but I'm launching the existing one.

[00:09:13]Okay, are you understanding now? So ensure when you're launching Eclipse the first window that you will see here is called as a workspace window. So what is this workspace window? What do you mean by workspace window? See workspace here is the location on your computer where you want to store all the projects that you're creating in Eclipse.

[00:09:46]Let's say I created one Java project.

[00:09:49]Where will this Java project be stored?

[00:09:52]So I have given the workspace G drive/ May 2025.

[00:10:00]This is what I have done here, right? G drive / 2025. Now you can also browse and change this. Okay? You can create any other folder. Right click, new. I'll create a folder here. Let's call this folder as uh let's call this folder as let's say main okay underscore code.

[00:10:30]Give any name that you want to give. Now what will happen once I launch Eclipse?

[00:10:36]All the projects that I create in Eclipse will be by default present inside this folder on your local computer. So let's click on launch now.

[00:10:48]Okay, let's click on what? Launch now.

[00:10:51]Okay, I hope you guys are getting the steps quite clearly.

[00:10:56]only after installing JDK you should install Eclipse because Eclipse runs on top of JDK.

[00:11:06]Okay, without JDK you cannot launch Eclipse. Keep this in mind. Okay, so this is very important. If you want to run your code inside Eclipse, Eclipse uses JDK. That's why I first installed JDK. Now you'll get a welcome window.

[00:11:22]You can just close that. And here the project explorer is the one where you see there are no projects in your workspace.

[00:11:32]Can you tell me what is workspace? Just now I explained. Can you tell me what is workspace?

[00:11:38]It is the physical location on your computer where all your Eclipse projects are going to get created. In your case, I gave the workspace in G drive may code is the folder physically all the projects that I create should be present within that. Let's check this.

[00:12:00]So I'm going to create a new Java project by going to file new file new and you select if you don't see a Java go to others and type here Java select.

[00:12:14]And then after you're going to now give that project a name app Java_1 and I'm going to select the second radio button which says I'm going to use JDK 21 accordingly whichever version your Eclipse is using it you can see this here in the drop-down this tool Eclipse has picked up 21 from my okay installed series of Java I have Java was 17 20 21 right 20 you know six things like that specifically by default it is using 21 and now I'm going to click on finish now see moment I created this project you can cross check this now you just go to your G drive you have a folder called as my may where is that may code is a project created within Is my project within the workspace?

[00:13:16]Yes or no? That's why when you launched Eclipse, you gave the path with a folder name. You gave the path with a folder name specifying where do you want to store all your projects and that's called as a work space.

[00:13:38]Okay. So now going forward if I create 100 projects in Eclipse here all 100 projects will be present in same folder.

[00:13:47]Now the next thing is I'm going to create okay I'm going to create here a Java class. So just click on right click on src go to new select class A and you observe the font size is too tiny. Hey online students, I hope you're all able to follow me. If you now observe here, you see the point is you can have any numbers of JDK go. It's not that 1.8 is there. I cannot use 26. Latest version of Eclipse will not support 1.8.

[00:14:28]your recent versions Eclipse 2025 or the recent one requires JDK 21 and above. So you might not be able to use Eclipse with the older version. Minimum 21 would be required with the latest versions of Eclipse.

[00:14:45]So even if you have 1.8 date still have to install 26 otherwise Eclipse would not work and you'll end up using very old version of Eclipse like Eclipse launched in 2014 15 2014 12 almost 12 years back version of Eclipse you'll have to use that to give that compatibility okay you see that the font size is quite small so how do I increase the font size control ++ on your keyboard just Press control ++ and the font size would increase and control minus minus would reduce the font size. So this increases and this decreases increases decreases minus min - plus+ increase.

[00:15:31]Now let's go back again here and you will find github.com/ you can just give my name okay pankage muta4 and now click on this 10th June and here you will have lot of shortcuts that's been given in the notes I'll just press Ctrl F and type shortcuts shortcuts.

[00:16:03]Can you see that important shortcuts in Eclipse that you should know? Okay. Then we will look at the debugging part. So what are the important shortcuts? If you do not know the shortcuts, you will not find your tools to be handy.

[00:16:22]The shortcuts makes your development faster and easier.

[00:16:28]Example, I want to add a main method.

[00:16:31]So, we just type main and control spacear is a content suggestions.

[00:16:40]It will suggest the content, right?

[00:16:42]Content assist meaning just press control spacear control spacear and you see it suggests that you can select this and I will create the complete structure of main right you want a system dot outprint ln don't type it in eclipse syso control spacear and now if I type 100 and you see there's a run button here.

[00:17:17]Here you can click on that but I prefer right click run as Java application I got the output in the console.

[00:17:27]So many times when you want a suggestion to complete something then use control spacebar a very important shortcut.

[00:17:38]The next thing this is like very very important when you're working with Eclipse and every tools they have got shortcuts.

[00:17:48]I'll teach you all that shortcuts as in when we pick the required tool like IntelliJ I will teach you the shortcuts there as well. Okay. Whatever shortcuts you see in Eclipse, same shortcuts you will see in other tools as well but the shortcuts will be different. But feature is same.

[00:18:09]Okay. Now let's look at what if I have an error in the program.

[00:18:16]Now usually earlier people would go to Google and do a research on the errors. People would go to Google and do the research on errors.

[00:18:31]Right? Today people will go to AI tool and they'll ask what is wrong here?

[00:18:36]Correct this.

[00:18:37]But actually this small small errors that you see in your program we already have the shortcuts in your tool to resolve that.

[00:18:48]Now most of the errors that you see in Eclipse just take the cursor on that error and press control 1 and it automatically gives you a suggestion what needs to be done in order to resolve this error. It says change method return type to int. And there you go. The error is gone. Yes or no? I hope you're understanding this.

[00:19:16]Suppose I have an error here. Int x is equal to I'm storing the value mic. And now when I place the cursor here, you see that press control 1 already there's a solution given. change the type of x2 odd string.

[00:19:36]Control 1 is a very important shortcut because whenever you see any errors in your code, it'll give you a quick fix to it. Let's take more examples given in the file here. Right? Right? I think we've already taken few of the examples but I'll keep using this during your training so that you will get a fair idea about how to use these shortcuts.

[00:20:05]Okay. Whenever you see error go to the error press control 1 and that will give you a solution how to fix the error.

[00:20:14]Online students please tell me are you clear with this part? Did you understand what we have done so far? Right? See okay might be I agree to one fact. I would like to tell my students one very important fact. My energy level is not same as how it used to be right few years back.

[00:20:38]Right. So there is somewhere wobbling of energy level. Okay. And thing is yes you know I am getting little tired more quickly. So could be like lot of stress and I've spent almost 18 years training students. So I would not deny telling that yeah you know there is a kind of little bit here and there you know stress okay on me and please cooperate a bit the way I'm covering up the syllabus will not be compromised okay that will never happen but uh since I've already taken the commitment of your batch I'm not going to call that off let me be very clear on that right but whatever batches Right now I'm taking it or executing the batches is we will do it with discipline but sometimes when I'm not able to come to the classroom and take the class be ready with the laptops especially offline student and take the live class in the laptop okay that small cooperation would be expected okay is this clear everyone yes okay so yeah you know uh I am facing those challenges this okay so instead of watching it on the bigger screen you guys can probably take a laptop and switch on the laptop and I'll tell you that in your group that today my class will be conducted online so take it otherwise I'll come offline and take it okay great now let's continue further uh because I don't want to do any hide and seek with the students I just would like to be very transparent and clear about it right both the formats the classes will go But I assume the quality of training will not be compromised either way.

[00:22:32]Okay? Right? So I'm going to take one example now. Let's take this up. So I have a question for you. Now I'm going to paste this in here. Now you see an error. So which shortcut will you use to resolve the error? Just now I talked about which shortcut will you use to resolve the error? You'll press control 1. And now you will select rename the file. You see that moment I got an error I could resolve that. But see guys when you're working on a project the class that you're working on will be a very big class. There'll be hundreds of methods, hundreds of variables, hundreds of lines of code. So much of content is present in that. And now we want to see the complete content at once. what is present in the class. I want to see that as a summary like when you pick up a textbook definitely you will firstly look at the index of the textbook because that index is like a summary that tells you that on which page number what topic is been explained. Yes or no? Which page number?

[00:23:48]What topic is been explained? You can just get that from the index number.

[00:23:53]Then you follow the index and you can directly go to that topic. Yes or no?

[00:23:58]Agreed or not? Imagine you don't have an index number in your textbook and now your textbook is of let's say 2,000 pages and you want to find a particular content. Is that easy or difficult?

[00:24:13]You understood my question. What is the question? I said what is the question?

[00:24:21]You have a textbook without an index.

[00:24:24]Okay. You have a textbook without a index page. The index page, what does it consist of? The topic name and the page number. Yes or no? Now the point is if that index page is not there, then finding out a topic and going to that page number is very difficult for me.

[00:24:45]That's a summary. Index is like summary.

[00:24:47]What your textbook consist of? Same way when you're in this class animal so many content in this I want to summarize and screenshot so we press control O and it very clearly says look there is one variable called as name there is one method eat there is one method sleep there is one method breathe there is one constructor called as animal we don't know what is constructors right now I'll definitely discuss about that later but now see imagine it had some 50 60 methods I can just see the complete structure by control O and is very important on large scale projects because I can now just click on it and directly go to that method. Okay, I can directly go to what that method. Okay, see you click on that directly it goes to what read method. It directly takes me to that method. It's like the index of your textbook.

[00:25:41]Which page you want to go to? You check the index, get the page number, scroll through your book and go to that particular page. So this is again a very important shortcut. How many shortcuts covered so far? Can you please tell how many shortcuts are covered so far?

[00:25:57]What's the first shortcut?

[00:25:59]Very good. Control + space. What is the next shortcut?

[00:26:03]Control + 1. What is the next shortcut?

[00:26:06]Right. Excellent.

[00:26:08]Now we're going to look at one very important feature which is F3.

[00:26:16]See let's say you're going through your program and somewhere there are some variables that has been used. Example let's say I'm just using here some variable.

[00:26:31]Okay. And this variable that I'm using, I'm going to create an object of animal a is equal to new animal. And now what I'll do, I'll just call this a dot name.

[00:26:49]Now imagine you are in a class which has 5,000 lines of Java code. How many how many lines of Java code? 5,000 lines of Java code is present. And you want to know this name variable where is it declared right? One of the way to do that is you can of course press control and find that out. Another way is just place this here cursor on name and press F3. It directly takes you to the declaration.

[00:27:20]You see did it go there? Observe declare means where is this variable created?

[00:27:24]Where is this variable name created? So go to that variable and just place a cursor and press F3. You see it directly takes me to the place where this variable is been declared.

[00:27:43]Okay. So this is another cool feature.

[00:27:46]Then control + dot. See what this does.

[00:27:50]Imagine I have series of errors in my program. I have series of errors in my program. Now I want to jump from one error to another. Okay, there's the first error. Now I need to go from one error to another. So we just use control dot control dot. What this will do, it will automatically take you from the very first error to the second, from the second to third, third to imagine you have a 10 errors in your file and you want to resolve the first error, then go to the second one. So you just after go to the first error and press control dot. It will automatically take you to the second error. For example, say I resolved this error. Now press control dot. Now let me resolve this error. Now press control dot. You see resolve this error.

[00:28:40]Yeah. So this control dot jumps to the errors in sequential manner. Okay. See with practice you will get familiar with it. Right? Currently remembering all the things will not be possible like this.

[00:28:58]Students have to keep practicing.

[00:29:00]Students have to keep doing things practically.

[00:29:03]Then only you guys are going to get familiar with it. Okay. I hope you guys got this now.

[00:29:13]Sure. Okay. Good. Now we going to look at Okay. So now we got some shortcuts and stuff like that. But then I'm going to now begin with a very very important concept right that's debugging.

[00:29:31]So I'll take you through some basic debugging rules. Okay. So let's delete this A. Now there's an error which is the shortcut you will apply here. Control 1 and that resolves the error. control one and that resolves the error.

[00:29:52]Now please understand right when we guys are talking about see nar I'll have a detailed discussion with you on a personal note let's not take this in the class right now I'll connect with you on call give me some time because first I need to understand why 4 years you could not complete the course right so give me some time now observe here the first thing that we guys need to understand how this debugging actually works. What are the controls we have it in debugging? Let's take a very simple program. Let's take a very simple program. I have two methods. I hope you all understand methods now. And here I'm going to write now from test. I'm going to write here from test. And let's write a a1 a1 is equal to new a new a and then a1 dot test and let's also write some code here. Okay. Now firstly understand what is debugging.

[00:31:06]I would not say that just with today's class you will become experts in debugging.

[00:31:11]Program is simple. Without debugging also we can understand but when you're working on someone's else project usually when you join the company people have already developed the project code there are one lakh two lakh lines of code written down and you need to understand the code that has been developed by someone else.

[00:31:36]How will you understand the flow of it?

[00:31:39]What is happening? Each and every line of the code what is it doing?

[00:31:44]Today as a student you have a doubt you might ask your batchmate hey can you please tell me how is this working or you might come and ask me but you cannot do this in companies right a huge code right you need to learn to understand that by yourself you need to learn to understand that by yourself now how do we do this now so this is where debugging comes in picture. Okay, tomorrow somebody says there is a problem in your code.

[00:32:19]Firstly, you need to find out where is the problem. Then what is the problem?

[00:32:24]Like you go to a doctor and first thing is doctor will run some test blood test ECG XY Z things and then after the doctor does this running these test once the doctor does this now firstly found out what the problem is yes or no correct what the problem is or where the problem is let's check it where the problem is once he knows where the problem is he'll accordingly give a solution.

[00:32:58]So debugging also has two steps among that lacks of lines of code which line the problem is where is the problem.

[00:33:08]First you need to find that line number and then what is the problem and give the solution. So guys understand here right debugging is very crucial because without that you will never be able to find which line number has the problem what is the problem and if you don't know line number and the problem that it has got you can never give a solution to it for now we are debugging just to understand the flow but at the later stage debugging will be used basically to Okay, find a bug for now program flow.

[00:33:48]Later to find a bug, we will be using debugging. So the first control in debugging is halting a program at a particular line. So we put one small break point. You see that? Just take the cursor, double click. You see a small bubble icon here. Okay, probably on the projector not that clearly visible. But carefully if you look at line number six, there's one small bubble icon here.

[00:34:11]Yeah, if I double click that bubble icon is gone. Again, you double click the bubble icon is back. Now, what does this mean? Now, when I start my application in debug, my application will stop at line six.

[00:34:27]So that from line six, I can analyze the code step by step. You see now I'm at line six. I'm at line number six. It halted there. you know normal execution flow program will not stop at any line but now I'm stopping my program at line six and now I want to move from line six to 7 I want to move from okay line six to 7 I want to move from my current line to next line the current line number is what six what is the next line number seven excellent so now there is a feature here called as Step over.

[00:35:11]Okay, when you do step over, this will just help you to move from the current line to next line. You click on this, it moves from the current line six and it goes to line number seven.

[00:35:27]Again you want to move from the current line to next line. How do you move from the current line to next line? You have to again use step over only.

[00:35:37]Right? Again you want to move from the current line to next line. The current line is eight. So next line will become nine. It just moves from the current line to next line. Did it move?

[00:35:49]Now there's a closing bracket of main.

[00:35:51]So program has to stop.

[00:35:53]We could not go to this method because that control could not take me to that method.

[00:35:59]Again carefully observe. I'll run this in debug mode. Now this is called as a debug program flow thread. What does it mean in layman terms? Forget about all this complicated term. Which method you are in? It says you are in main method.

[00:36:16]This main method belongs to which class A. And which line number inside that method you are at? I'm at line number six.

[00:36:25]This gives you which line number, which method, which class currently you are in.

[00:36:34]See now when I do a step over what step over does moves from the current line to next line did the line number change now you're still in main method class A line number seven again you're at line number eight now line number nine closing bracket and stop. So if you notice step over step over has a potential to move from the current line to next line but it's not going to the method that I'm calling. See from line 8 it'll not go to this line 10. This step over cannot do it. Then how do we do this now? So that's where the next control comes in picture. When you do step over from six it moves to seven.

[00:37:19]From seven it moves to eight.

[00:37:21]But now I see as a developer that at line 8 there's a method calling statement and I wish to go to that method. So you cannot use step over. If you use a control step over, it will move from the current line to next line.

[00:37:40]But it will not go to the method that it is calling. If I now to step over, it'll directly go to 9. But you wish to analyze for some reason you want to analyze the logic of test method.

[00:37:53]And to analyze the logic of test method, you'll have to go to that method for which we use a control called a step into the shortcuts also given F5 and for this F6 on your keyboard.

[00:38:07]Okay, right now I'm manually clicking on it or you can use F5 and F6 as a shortcut. Just do a step into and when you click on step into you see now it goes to that method otherwise the controller is not going there. From one method you want to go to another method during the calling statement which is that method the calling statement is calling.

[00:38:34]Suppose which method is that calling statement calling? You want to know that then you step in. Now when you go to step into I reach that method and now I want to move from the current line to next line. Which is the next line? Line number 12. It prints from test. You can see here.

[00:38:54]Now from the current line 12, it should move to the next line. So this will automatically go now line 12 will go back to line 8 and stops at next line.

[00:39:05]I'm using step over closing bracket of main method. Step over. Did you guys understand this?

[00:39:13]Please tell me. Online students, did you understand this? Please tell me. See you going forward. You know what I want my students to be capable of is not ask your friends or someone else how this program works. What is the logic?

[00:39:32]If you know debugging, you will start understanding the logic by yourself.

[00:39:37]That important this tool is. But for now you will not understand. So we just understanding the flow. At least now you're understanding the flow. Later the logical understanding also we can explore with deep again. So today I have talked about today anybody joined late to please repeat my again the recorded class once again. But now see today I just talked about this bubble icon.

[00:40:06]Wherever you want to stop your code during debug, put that here. And then you click on the debug mode like this.

[00:40:14]So this is the first thing that I talked about. When I click on the debug icon here, this debug icon, when I click on that, this is called as a break point that stops my application at that line. Now if you want to move from the current line to next line, we use step over.

[00:40:33]Which is the current line? Six. Which is the next line? Seven. If you just want to move from the current line to next line, keep using this control.

[00:40:42]Current line to next line. 7 to 8. Use this control. 8 to 9. Use this control.

[00:40:48]This will only move from the current line to next line. But this will not line 8 was calling a method, but this will not go to that method. Step over can only help you to move from the current line to next line. Since that's a closing bracket of main program stops.

[00:41:08]You saw that what happened here when I did step over current line to next line.

[00:41:12]Step over current line to next line.

[00:41:16]But from line 8 I wish to go to line 10.

[00:41:21]From line 8 I wish to go to that method and analyze that method test. If you want to go to that method, you want to enter that method and analyze. Then step over will not work. From one method, you want to now go to another method because there's a method calling statement. So you know as a developer whenever a method calling is happening, it's calling some method. I want to go to that method and analyze. Now to go to that method during your debugging, we use step into.

[00:41:53]Now again from here you want to move from current line to next line. Which control will you use?

[00:41:57]Step over. Now from this current line, I want to move to the next line. So obviously line 12 will go back to eight.

[00:42:04]Step over current line to next line.

[00:42:06]It'll go to line 8, but it'll go to line eight and stop at line number nine.

[00:42:12]And 9 is a closing bracket of main. So the execution has to stop here. So I'm going to talk more about this more about debugging part in my tomorrow's series of lecture. We're going to discuss more about it in our tomorrow's series of lecture. How this debugging okay can be used and further all my teachings it will include debugging most of it. So when I teach you anything, I'll just open up the debug controls and with that I'll make your learning easier.

[00:42:52]Is this clear? Is today's class clear for all of you?

[00:43:00]Yes. Any doubts? Any questions? Any queries? No doubts. No questions. Online students, do you have any questions for me? You have any questions for me?

[00:43:12]Anything else? No questions. So far, all of you, you're clear with it.

[00:43:20]See, once you acquire the skills, see, getting interview calls is not going to be challenging, right?

[00:43:32]See, Joti, I want you to just once look at the recorded classes.

[00:43:37]Uh, that's a suggestion. Slowly pause the video and again try to catch the same thing. Since you're going to get the recorded classes right that I've taken it on YouTube is going live. I'll share the link for your reference. Hold on. You just copy it and keep it because today staff is not there.

[00:43:59]Uh staff she is on leave. So I'm sharing it manually here. Is this clear? I'm sharing that here quickly. Everybody copy that and keep this link with you.

[00:44:14]And I wanted to just go through this once.

[00:44:18]Right.

[00:44:23]See, I already said I will get back to you. You need to give me some time and I will definitely connect with you.

[00:44:32]Okay.

[00:44:36]So you see this the link.

[00:44:42]Okay. I think this is the link. Yeah.

[00:44:44]I don't know.

[00:44:55]Did you copy all of you? Yes.

[00:45:00]All of you. Did you copy this? Online students please copy it. and online student directly can go to my I'll also try to share it in okay let me do one thing I think I do have uh I'll send an email to myself with this link so probably after the class I will sh no no see the thing is there are two types of code written down one that I'm developing.

[00:45:39]The other code is which is built-in Java feature.

[00:45:43]Now debugging is a concept where we debug the programmer's developed feature. For example, you're doing system.out.print ln. Now debugging that print ln statement is not my scope of work. Why would I debug that? I have not developed that.

[00:46:04]That is not my work. That is developed by Java JDK people who have developed that programming language. They have already debugged it. They're already claiming that the feature is fully functional and defect-free. And that's not within my scope of debugging.

[00:46:22]See you need to understand debugging is a concept which as a programmer I will purely apply on the logic and the code that I have developed. Did I develop how print should work? Did I write that logic system.out.print ln how this logic should work? Did I develop or that's a built-in Java logic.

[00:46:46]So why would you debug? My f first question is why would you debug the internal logic?

[00:46:53]See my question is very simple to you.

[00:46:56]The question is why would you debug what exactly Java people have done internally.

[00:47:05]Right? So we're going wrong. Nobody does that debugging.

[00:47:10]Not me. None of the developer will do that because that's out of my scope.

[00:47:16]Right? That's out of my scope. This is not your area of debugging.

[00:47:20]And you can't even debug that. Another reality of that is you can't debug that.

[00:47:27]Okay? Because complete code of Java will not be exposed.

[00:47:31]Example further when you are doing something there are a lot of internal code. We don't have the access to that.

[00:47:38]We are restricted to debug that because that is exposing the internal logic.

[00:47:43]Okay.

[00:47:45]So this is purely restricted to the developers what they have done like I've developed test method I can debug that but not the methods which are internally developed by JDK like system.print not print len you will never debug that that's out of scope so that's a wrong message we are passing on that if you come across somebody educating you that we should do that is wrong you're not you're not finding defects in programming language you're finding defects in the application that is developed using programming language I hope you got this what I'm telling you so you have to bifocate your debugging thought process into two different angles.

[00:48:36]Yes, use any ID. Every every idea has got debugging. We'll also debug in intelligj.

[00:48:42]We'll debug in every tool that we're going to use. If you're not going to restrict only for this so that is something which we will definitely take care of it.

[00:48:51]Huh?

[00:48:54]What?

[00:49:04]See there are two kinds of bugs Eclipse cannot fix. I said we can resolve the errors. See understand bugs are different. Bugs are sometimes logical sometimes technical. logical bug is example imagine I'm trying to now enter 601 and my ATM machine is taking that input so that shouldn't have taken that input now that's a logical bug right that's a logical bug the logic that you developed in your code is not proper this is what you need to debug that where is that logic that needs to be created where the input given by the user should be only multiples of 100.

[00:49:55]It cannot be given a 6.1.

[00:49:58]Now that logical bug again coming to your answer is that logical bug you created. Why will you go internally to the Java code and debug that one? Now no still there is lot of maturity you will build. See right now you're at a very early stage. So I understand as a student you might get such questions for now because we are not totally at that mature level thinking of how debugging happens. So there are a lot of things we have to take care of. So right now we might only have some basic uh stuff in mind that okay you know it should work this way that way but just give some time with time you will have more understanding. Suppose a tester reports a defect. How I have to start finding out where the problem is, where the defect is, which the testing team communicated to me. And we will then eventually look at basically some more things like some more things like okay now the defect is here. How do we fix the defect? That's another thing we people are going to look at. So we have to give time guys. Okay? And you might not find this on YouTube which I'll be damn sure about it. You cannot find this information on YouTube.

[00:51:28]You can check that out because they might just teach you the controls. But the actual thing is when you're working on a project, the tester will just give the defect and you don't even know which part of the code that defect belongs to.

[00:51:43]Right? That code has been developed by some other fellow sitting somewhere in US.

[00:51:49]He has developed the code.

[00:51:52]That fellow has developed the code somewhere sitting in US. Let's say a month back and today the defect has been given. But they're telling the developer in India telling you fix it and you don't. Now what is your first step you're going to take here?

[00:52:08]What is the first step you're going to take here?

[00:52:12]Huh?

[00:52:15]First my question is how will you find out which part of the code there is a bug?

[00:52:22]There is one lakh lines of code, two lakhs lines of code, five lakhs lines of code. They're just telling this is the bug.

[00:52:36]No, it is running on server. Where is the code accessible to tell the number?

[00:52:43]It's running on the server. Server you cannot find out the line number there.

[00:52:50]Huh?

[00:52:52]See the point is the research has to start there. As a developer we'll follow URL looking at the URL that URL is making a call to which line number which method. So there are detailed steps that we will have to take it right. Right? So one way is we might just listen to some theory part and okay yeah this is done yeah this is okay but see this is where we will get into more detailed thing as we proceed further right right now I'm running a local computer you can say oh this is the line number right but we cannot do it that way that's not the way so there is a lot of learning that will happen eventually and it will take time as well okay so have patience don't rush that is what I would recommend and also please avoid giving inputs to other candidates when the information is half because that becomes a total misguidance right we have to understand the things in actual how it works that is what I'm trying to give it to you so sometimes I've seen this among the student not pinpointing at anyone we know half of the information and we just want to paint the picture of our knowledge to someone telling that look I know a lot of things and somehow he becomes a victim of that with half information and he starts believing and the road map totally changes and he creates a dead end for himself.

[00:54:28]This is a very serious thing. Sometimes I get this comment s some students in my batch they already know lot of thing about Java. Now the question is if they know already lot of thing about Java why are they in my class let them join some company I have a straightforward question why you put not I'm here only for placements all right then directly I'll give you interview calls so then I will directly give interview calls and tell that okay I'll give you interview calls when you get placed you give me money see it is a very different ball game altogether okay so a slight deviation A slight misunderstanding, you're gone.

[00:55:10]Okay. Right. Bye, guys. Take care.