12th may 2026 - Core Java Demo Session 4

本站添加: 2026-05-26

[00:00:46]Okay.

[00:00:47]So, the last lecture we guys had discussed about types of variables that we have written Java. Right? That is what we had discussed in our previous session.

[00:01:01]What are the different kinds of variables we have? So, can you just quickly tell me what all kinds of variable do we have?

[00:01:09]Come on, one by one, loudly. People, you need to tell that what all types of variables are there. Which is the first variable we discussed?

[00:01:20]We discussed about local variable.

[00:01:24]That's the first one.

[00:01:26]Then after the local variable, what is the next thing we are going to now look at is static variable.

[00:01:36]Static variable. Then after that we discussed about Come on, guys, you need to mention that in the chat box. What is the third one?

[00:01:45]Non- static variable.

[00:01:49]And then after we discussed about reference variables.

[00:01:55]Okay? So, these are the four categories of variables which we studied in our previous lecture.

[00:02:04]And the notes for the same is already present in our GitHub link.

[00:02:10]Okay?

[00:02:11]So, let's open the notes.

[00:02:13]Press control F.

[00:02:16]Let me open this up. Press control F and search for types of variables in Java.

[00:02:27]So, these are all the types of variables that we have.

[00:02:31]Now, let's continue further with the next concept in our today's class. Let's see what is the next concept.

[00:02:39]So, I'm going to talk about heap and stack memory bit later. I'm not going to discuss about this in today's lecture. I will talk about this later.

[00:02:49]But, firstly let's start discussing about what are methods in Java.

[00:02:56]Okay? So, we're going to learn what are methods in Java.

[00:03:02]So, the first thing we will understand in methods, what do you mean by void keyword? Now, what are these void keywords?

[00:03:11]See, void keywords are just like Vijay Mallya and Nirav Modi.

[00:03:18]So, what do you mean by Vijay Mallya and Nirav Modi? It means you never Okay, return the money back that you have taken from the bank. Which means these people, they took loan, but then they never returned back the money back to bank. So, void it means will not return any value. What do you mean by void? Void it means it will never return any value. Let's try to understand this more clearly with an example now.

[00:03:55]So, I'm just going to launch an IDE and also in tomorrow's class we will install JDK and Eclipse.

[00:04:05]Okay? So, for now, let me launch this IDE and we'll understand all of these keywords one by one in detailed manner.

[00:04:14]Okay? So, whenever a method is void, it cannot return any value. So, let me go to file, new, I'll create a Java project.

[00:04:24]I'll just create here a Java project.

[00:04:28]A Java project.

[00:04:30]Okay? Let me give it some name. I'll teach you all of these steps in my further classes. App underscore Java underscore one.

[00:04:41]Okay? And then, I will click on finish.

[00:04:46]Now, let's create a method quickly here.

[00:04:48]So, let me go here and I'm going to now create create a class called as A.

[00:04:58]Forget about what is this package, right? What is this public keyword, all of these things for now.

[00:05:05]Do not worry about that.

[00:05:07]We are going to create a main method.

[00:05:10]Okay? Not main domain, it is main method.

[00:05:14]And then, I will create public void and a test method.

[00:05:20]So, you notice the return type of the method here is void.

[00:05:25]Now, whenever you try to return value, return space value there is an error.

[00:05:33]Now, a method which is void can never return any value.

[00:05:38]I'm sure all of you you did assignment in my Okay, last I think last lecture, I had told you to complete assignments.

[00:05:48]Have you completed that? Data types and type casting.

[00:05:53]And then I had mentioned about I had mentioned about one more assignment, unary operator.

[00:06:00]I hope everybody has completed that. If anybody has not completed, please do complete those lectures. All the assignments that I give is very important. At the end, I'll again show you where the assignment links are. But let's come back here again.

[00:06:17]Now, you see that I'm returning 100.

[00:06:20]Now, what is 100? 100 is an integer value.

[00:06:24]100 is an integer value.

[00:06:26]Now, since you're returning an integer value, but the method type is void, you see that I'm getting an error. Void methods cannot return a value.

[00:06:38]Change the method return type to int.

[00:06:40]Okay, let me change this to int. Is the error gone? See, what value you're returning, depending on that, you need to keep the data type here. Example, I write it as void.

[00:06:53]And now I'm going to return some string value. I'm going to return now some string value. Now, when you return a string value, observe the method cannot be void. Since here it is a string value, you need to change the return type to string.

[00:07:13]Okay, you need to change the return type to string. Same way, if I'm returning a floating value, 10.3f, then the return type should be float.

[00:07:26]Which means, whenever a method is returning any value, please do not make the method as void. Let's come back to the notes. Read this loudly once.

[00:07:37]Void keywords.

[00:07:39]Okay, void keyword. A void method cannot return any value. Example one, a method is void, you're returning 100, it is giving an error. The reason for error is method is void and you cannot return any value here. I hope you guys are getting this now clearly. The first example was clear for all of you.

[00:08:04]Now let's, okay, learn more things about it now. So since I'm going to return here an integer value, change this to int. And I need to call this method because it's a non-static method, you will have to create an object. Now how did you know it is a non-static method?

[00:08:23]Because this method does not have static keyword. And because it is non-static, it belongs to object. So I'm now creating an object. And now I'm going to call this.

[00:08:38]Okay? Now very carefully observe, I will run this in the debug mode. However, how to debug an application people would not be clear as I've not taken classes on it. Later, I'll teach you debugging starting from tomorrow. How to debug, what are the steps we follow, basic level of debugging we should begin from tomorrow.

[00:09:03]Advanced debugging classes, I will take that during our API development lectures. So let's click debug icon quickly. Save the program and run in debug mode. Now when I run this in debug mode, observe.

[00:09:20]Okay, when I run this in debug mode, you see that our application stops at line number line number five.

[00:09:29]Now from line five, the control goes to line six. Now please tell me guys, you need to now tell me in the chat box, line six is a method calling statement.

[00:09:42]So, from line six, offline people, from line six, which line number will it go to?

[00:09:48]This is a method calling statement. From line six, which line will it go to? Very good. Very good. From line six, it will go to line eight. It will go to line eight.

[00:09:58]And stop at line nine. Observe.

[00:10:01]Sorry. Again, let me just show you the steps properly. I clicked on a wrong button while debugging.

[00:10:07]Now, observe here. You're at line number five. So, now you're at line six. Now, line six is calling line eight and stops at nine. See, it went to eight and stopped at line number nine.

[00:10:20]Now, what is line number nine going to do?

[00:10:23]Line number nine is going to return this value back to the place from where it is called from.

[00:10:31]Can you tell me from line number six, you went to line eight?

[00:10:36]Now, line nine will return back to the place from where this method test was called from.

[00:10:42]From which line number did you call this test method?

[00:10:45]Line number six. So, now this 10 value will go back to line number six.

[00:10:51]But, then when it goes back, this value that is given to the step, I need to store that in some variable, which I've not done it. It is returning the value 10 from line nine to six, but that value now, let us store that in a variable.

[00:11:12]Okay? So, now let us complete the code and we'll understand in a much better manner. Observe here now.

[00:11:20]Observe here now once again how the steps are going to be. Step number one, line five goes to line six.

[00:11:28]Line six, it goes to line number nine and stops at 10.

[00:11:33]Now, line 10 is returning the value 10 back to the method calling statement.

[00:11:39]You see that? Is it going back to line six? Yes.

[00:11:43]Now, what is going to happen at line six? Let's see this here.

[00:11:47]At line number six now, at line number six now, when I proceed further, the value 10 got stored in the variable X. You see, whatever value was returned from here to this step, that value got stored in X.

[00:12:02]And now, when you proceed further, it prints 10.

[00:12:06]Whenever the closing bracket of main method runs, the whole program execution comes to an end. See, now there's a small red button here. The program, it means it's still running. When the closing bracket of main method runs, you see what happened? It got terminated.

[00:12:25]It got terminated. So, there is one important thing students have to keep this in mind. What is that?

[00:12:33]He, program execution always happens to start program execution always happens to start Okay? With main method. Okay?

[00:12:47]And opening bracket of main method. I mean, this. See here.

[00:12:53]So, let us just highlight this here. So, this is the place where your program execution is going to start.

[00:13:04]Okay? This is the starting point. Now, this is a fixed rule.

[00:13:07]Always keep this in mind.

[00:13:09]And whenever whenever the closing bracket of main method runs, so this is the place where your program execution should come to an end.

[00:13:23]Okay? Should come to an end.

[00:13:26]So, keep this rule in mind. Always you start your program execution okay with the opening bracket of main and whenever the closing bracket of main method runs, the program execution has to stop. Okay? I hope this part is clear for all of you now. Everybody, did you understand this? If yes, then we'll start taking lot of examples to make you understand this in a more depth manner.

[00:13:54]Everyone, I hope you're clear part.

[00:13:57]Excellent. Anybody has any doubts so far? Right? You can ask me. And if not, let's move ahead with more examples.

[00:14:07]Now let's say in the next example now, I'm going to return here string. That is Mike.

[00:14:15]Now firstly tell me, the error here is because I'm returning string and here it is int. So what I should replace this with?

[00:14:25]What should I replace this int with?

[00:14:28]What kind of value are returning?

[00:14:29]String. So you have to replace that with string.

[00:14:32]Excellent. Now you see again there is an error here. Can you tell me why there's an error?

[00:14:37]You're returning Mike. You're returning Mike. But then, the string value you're trying to store in int. So change this as well to string. Now you're going to tell me the steps slowly, okay, how this is going to execute. Can you tell me from line five, which line number will it go to?

[00:14:57]From line five, which line will it go to?

[00:15:00]It will go to line number six.

[00:15:03]Correct? But now line six is a method calling statement. Line number six is a method calling statement. Since it's a method calling statement, it has to go to line nine, stop at 10.

[00:15:18]Line number 10, it will return this value Mike back to the calling statement. You see? Is it going back? Yes. You see the control came here. Now, the value, Mike, will get stored in X. And now, this is going to print Mike. Now, closing bracket of main method, if it runs, what will happen, students? Please tell me. What will happen?

[00:15:40]When the closing bracket of main method runs, just now I mentioned that.

[00:15:45]Yes, the whole program execution should stop. Okay? So, that's what the example we have taken so far that you see here.

[00:15:56]But now, we are going to talk about return keyword versus return value.

[00:16:03]Okay? Now, there is a difference between using only return keyword and using return space value. Let's understand what happens if you're using only return keyword.

[00:16:15]The first rule is whenever you're using only return keyword, that is only this. If you're using only return keyword, keep this in mind that the return type of the method has to be void.

[00:16:34]Okay? If you're using return keyword without any value, see, this is return value. And I'm not returning value. I'm just writing return keyword. Now, when you write only return keyword, then ensure the method happens to be a void method.

[00:16:52]Okay? Now, what this return keyword does here? Now, what does this return keyword does here? Let's understand this here quickly one by one. Let's understand the flow here now. Firstly, I will show you the flow. I will show you the flow on MS Paint, and then after, we will look at in debug mode. So, what will happen now?

[00:17:17]The first step that's going to take place here is opening bracket of main method, the program execution has to start. So, our program execution starts here.

[00:17:33]So, this is our first step. Step number two, object creation takes place.

[00:17:39]Now, step number three, you're calling this particular test method.

[00:17:45]Right? Now, step number four, you got the output as 100. Okay? Now, the closing Then, you see the step number five. This is step number five. Step number five, now what does this return keyword do?

[00:18:01]From here, it will just go back to the place from where it is called and stops at next line. Again, I'm repeating what the return keyword does. It just goes back to the place from where this method test was called and stops at next line.

[00:18:19]Now, this line is not going to print anything, so this line shouldn't have been there actually.

[00:18:26]So, what I'll do is I'll replace this with 100 because I don't have variable x now. Or 1,000.

[00:18:31]Okay? Or 1,000.

[00:18:33]Now, understand here, this should have been here 1,000. Okay? Anyways, we will rectify that in the actual program. Now, when this line runs, it should print 1,000.

[00:18:44]Finally, when the closing bracket of main method runs, the program stops.

[00:18:50]Okay, let's see this here, guys.

[00:18:52]Observe. So, now we have put a breakpoint here. Let me run this in the debug mode.

[00:18:57]Okay? We are at line number five. Let's move further.

[00:19:01]It's a method calling statement. So, from line six, which line will it go to?

[00:19:06]From line six, it will go to line nine.

[00:19:08]So, this goes to line nine and stops at 10.

[00:19:12]Line 10 prints 100.

[00:19:14]Line 11 will go back to line six and stop at seven.

[00:19:19]It goes back to line six and stops at seven.

[00:19:23]Line seven prints 1,000.

[00:19:25]Closing bracket of main program execution stops.

[00:19:30]I hope everybody got these things whatever we are talking about so far.

[00:19:34]Are you all clear with this part? Please tell me.

[00:19:37]Are you all clear with this part, students?

[00:19:40]Are you able to follow me?

[00:19:41]Okay. Offline students, I hope you are all able to follow whatever I'm talking about. Okay, very good.

[00:19:50]Now, since Okay, you know, you people want me to just hold on. I have here Okay, 1 minute.

[00:20:03]So, the next thing we people are going to proceed further and read these things. See, whenever you're using return keyword, ensure a method has to be void.

[00:20:17]Okay? You cannot use this in a method which is not a void. It is supposed to be a void method and it is optional.

[00:20:25]So, what do you mean by optional?

[00:20:27]Okay.

[00:20:28]Even if I don't write this, still the program execution will happen.

[00:20:33]But this time, because the return keyword is not there, the closing bracket of test method is the one from where the flow will go back.

[00:20:45]Observe here now. I'll just show you in the debug mode. Now, I've removed the return keyword, right? See the steps.

[00:20:50]You're at step six. Step six calls now nine, stops at 10, and now see, there is no return keyword.

[00:20:58]So, this time, the test method closing bracket will behave as a return keyword.

[00:21:04]If you don't write a return keyword, then this closing bracket is the one from where it goes back to line six and stops at next line.

[00:21:13]Observe. Stops at next line. Prints 1,000, closing bracket, and the program execution halts. So, this is optional.

[00:21:21]See, even if you don't write return keyword, still your program can execute.

[00:21:27]Suppose you don't write, then the control will return from here. And suppose you write return keyword, then the control from here has to go back to the place from where it is called and stops at next line. Is this clear, guys? Please tell me.

[00:21:42]Did you understand the meaning of optional here? Can you read this once loudly?

[00:21:46]Both the points.

[00:21:49]A method has to be void if you're using only return keyword.

[00:21:53]It is optional.

[00:21:55]It will return control to method calling statement. Yes, that is what is happening. You see?

[00:22:01]If you now observe this particular program, see what's happening. It's returning the control to the method calling statement. If you look at this diagram, we are calling from here, and then this return keyword is returning the control back to the method calling statement and stops at next line. That's the meaning.

[00:22:22]The program control goes back and stops at the next line. Okay, that is the whole meaning here.

[00:22:30]So, let's see these programs now one by one quickly.

[00:22:32]I'm calling c1. test. Now, when you call test method, it will print 100.

[00:22:38]Then the return keyword will go back to the place from where it is called.

[00:22:43]The next line is closing bracket of main. Program stops.

[00:22:47]Now, observe. The next thing is if you write anything after return keyword, let's take one statement, and let's add it after return keyword.

[00:22:59]If you write anything after return keyword, then that code can never uh run.

[00:23:06]Okay, that code can never run. Let me show you that here on MS Paint again.

[00:23:12]What does this mean? See.

[00:23:14]You guys are making a call to that method from here.

[00:23:19]Then it is supposed to print 100. This is okay.

[00:23:24]But now when this line runs, the control from here itself it will go back and stop at next line.

[00:23:31]The control from here itself it will go back and stop at next line.

[00:23:36]Which means this line of code will never execute. So, this line of code will never execute.

[00:23:48]Okay, so why we got an error is because this code can never execute and such errors are called as unreachable code error. Okay, so this is a designing flaw.

[00:23:59]You've written a Java line of code which can 100% cannot run. And such errors are treated as unreachable code error. Can you read this?

[00:24:09]If we write code after return keyword, then that code will 100% not run. This error is called as unreachable code error like you see here.

[00:24:22]This line of code can never run because from this line the control will simply go back and this will never get the chance to execute and throws this error. So, be very careful.

[00:24:33]After return keyword if you're writing any code, then that code is not going to execute, guys. Okay?

[00:24:41]Now, the next thing. Let's understand the next thing here now. So, what about return value then? So, we are understanding the differences, right?

[00:24:48]Differences between return and return value. So, we understood about return keyword quite clearly. See.

[00:24:54]Return keyword when you are using one, okay?

[00:24:58]Here, somewhere here. Correct, no? A method has to be void. It is optional to use.

[00:25:05]It will return control to method calling statement. But we are not looking at Now, we are looking at return value.

[00:25:13]Whenever you're using return value, method has to be not a void method.

[00:25:18]Example, see here.

[00:25:21]So, what I'm going to do now, I will change this to int.

[00:25:25]Since a method is not a void method, okay? The method is not a void method, it is mandatory to write return value keyword, otherwise this error will not be gone. You have to write here return some value.

[00:25:42]Now, if you don't write that, you see there is an error. Can you observe here?

[00:25:47]So, whenever method is not a void method, return value is mandatory.

[00:25:53]And whenever you're writing return value statement, method has to be not a void statement. Observe.

[00:25:59]Return value. The method has to be not a void method. The method has to be what?

[00:26:06]Not a void method. Second, it is mandatory to use return value statement inside not a void method. Are these two lines clear for students? Please communicate.

[00:26:18]Are these two lines clear for students?

[00:26:21]Please do communicate.

[00:26:23]Yes. Yes, everyone clear?

[00:26:26]It will return control and value to the method calling statement. See what is happening?

[00:26:32]When I now call this method, what we are telling is this is going to return the control and value back here.

[00:26:40]Let me write int x is equal to and let's print here let's print here x. Now, see what is going to happen.

[00:26:50]So, when I run this in debug mode, okay, there are two things that's taking place here.

[00:26:56]The first thing is this will return the control back.

[00:27:00]Control means from line 10, the program execution flow control will go to six, which means after 10, line six has to run.

[00:27:09]So, this decision, which line to run after 10, that control sending back to the calling statement is done by return keyword. Second, it is also returning value.

[00:27:20]Hence, that value is getting stored in X. So, there are two things happening.

[00:27:23]Program control flow is coming back here, and the value is also been given to the method calling statement. That is where we are telling it will return control and value to method calling statement.

[00:27:37]Is this part clear?

[00:27:39]Right? So, can you now tell me quickly?

[00:27:41]Some questions for you. Can you tell me why this method is throwing an error? If you've understood the concept nicely, you're going to answer this now. Why this method is throwing an error?

[00:27:51]Why this method is throwing an error?

[00:27:55]Why this method is throwing an error?

[00:27:58]Students, online students.

[00:28:00]Because the method is int, it is not a void, and whenever it is not a void method, if I don't write a return keyword, what do you see here?

[00:28:09]Error. What do you see here? Error. So, this is very important that whenever method is not a void, return keyword has to be there.

[00:28:20]You see?

[00:28:21]There is int return value keyword has to be there. It is mandatory. Since I did not write that, I'm getting an error.

[00:28:29]Error because return value statement is missing inside the test method. Okay?

[00:28:36]Next.

[00:28:37]Now, can you tell me what error I will get at this line? Just few minutes back I mentioned that. What happens if you write any code after return keyword?

[00:28:46]What happens if you write any code after return keyword, can you tell me?

[00:28:52]Yes, very good Gaurav, very good Wanshika. Right, error. What error is that called as? Unreachable code error.

[00:28:59]Now, this code can never execute.

[00:29:03]If you write anything after return keyword, then that line of code will never execute and hence you will end up getting unreachable code error. You will end up getting unreachable code error.

[00:29:19]Okay.

[00:29:20]So, the next thing Okay, so do you want to practice this much?

[00:29:25]Or should I continue further?

[00:29:27]Do you want to practice this much or should I continue further?

[00:29:32]Shall we continue further?

[00:29:34]Okay, good. Now, observe. Method arguments, understand here now.

[00:29:39]What are these method arguments, by the way? See, many times we might have a requirement to supply some values to these method. And that's very commonly you know, we'll keep seeing that in our project work as well.

[00:29:54]But, let's do one thing now.

[00:29:55]I want to supply a value to this method.

[00:29:58]So, to supply a value to this method I will create in this method something called as an argument.

[00:30:06]Okay, this is called as a method argument, which is responsible for receiving value from the method calling statement at line six, like this.

[00:30:19]Now, line number six which is going to call this method, to this now we are going to supply 100. We are going to supply what? 100. So, now this 100 will get supplied to this X. Now, this X is an argument. It's a method argument and it is treated as a local variable.

[00:30:40]Now, what do you mean by local variable is Now, what do you mean by local variable is I can use X only within the test method. So, suppose I print here X, you observe now this value 100 is given to X and now when you print X, it will end up printing 100. You supply any value to it now, but ensure the number of values matches with number of argument and type of argument. If it is int, the type has to be int. You run, it prints 500. You can supply any number of arguments, any type of arguments like this, that doesn't matter.

[00:31:22]Like in this case we have 500, then we are supplying 10.3f.

[00:31:28]Then we are supplying, okay, 10.3f has to be the third value because here the second argument given by me is a string. So, I'll call that as Mike. See?

[00:31:40]The same sequence you have to supply the value.

[00:31:43]Okay, first int, then string, then float. So, first int, then string, then float. And now let us print this value one by one.

[00:31:52]Okay? Let us print this particular value one by one.

[00:31:58]Now, when I run this program, observe we got the output 500, then we got the output as Mike, and then 10.3.

[00:32:08]I hope this part is clear for all of you guys. Right? It's clear for all of you and you don't have any confusions with regards to this. Excellent.

[00:32:19]Okay. Now, let's take more examples now.

[00:32:22]Now, there's another thing that we can do here. What is that?

[00:32:26]So, suppose if I give the method type as object. You know, suppose I type here as object. We'll discuss further what is object.

[00:32:37]Then whenever the method type is object, what it does is it can store any kind of value in it.

[00:32:44]You supply integer, see, it's getting printed.

[00:32:48]If I'm now supplying a character value, a char value, you see, it's printing that. You supply here a boolean value, true.

[00:32:59]You observe now, it is even okay, taking a boolean value. So, when you make the variable type object, it can store any kind of value in it. It can store any kind of value in it.

[00:33:14]Okay? So, I hope this part is also clear. Let's proceed further. Observe now.

[00:33:19]Now, there's one more interesting thing in Java wherein suppose let's say right here int followed by three dots.

[00:33:29]How many dots?

[00:33:30]Int followed by three dots.

[00:33:33]Now, here when I do that, you can supply any number of values to it.

[00:33:40]Any number of values to it you can supply. Like 10, then 20, then 30, then zero. You see, all of these values I'm able to hold that in one single variable.

[00:33:52]And this variable values to access, the first value you will access at zero with index.

[00:33:59]Likewise, the second value to access, you will access that index one.

[00:34:06]The third value you will access at index two.

[00:34:09]And the last value you will access at index four. So, that's the last value, fourth one. Sorry, that's three, not four.

[00:34:17]So, this is zero, then one, then two, then three. But, if you observe, one argument, suppose that a three dots, then one argument can take okay, multiple values in it. And hence, I get all the output.

[00:34:31]Now, with this now, if you're supplying some more values, let's say you're supplying now a mixture of value mic.

[00:34:37]And here, if I take it as string, y, you see it is giving error.

[00:34:43]So, whenever you want to give a sequence and series of values, and then you want to give some other data types, do not do it this way. Just keep this logic in mind.

[00:34:57]Firstly, give the individual data types.

[00:35:02]Individual means mic is one single data type, and here it is sequence of integer value. So, always start with a individual okay, data type like this, and then after you okay, capture the sequence of value that is in x.

[00:35:19]Did you understand this part?

[00:35:21]Because mic is a single value, keep that data type first, and int {dot} {dot} {dot} x should always come at the end.

[00:35:29]Example, I'm supplying now 10.3, which is a double value. Then here, you have to give double double okay, d.

[00:35:40]Observe now.

[00:35:41]Ensure that this is kept always at the end, okay? So, the sequence of value that you're supplying should be kept always at the end, and one which is not a sequence of value, that individual values, you start supplying in the beginning.

[00:35:55]Now, if you print y, you see what output will it print. And now, if you observe, if you now observe, we print here we print here d, we print here d, what does it now prints? Run this and see. We got the output. Is this clear, guys? Please tell me. If string is in sequence, then you just change this to string, no?

[00:36:21]See, one sequence is what? Now, you're telling that okay, string is in sequence, and I will Okay, let's say double is in sequence, and your question is can I use this? No.

[00:36:29]This is not allowed. int dot dot dot x can be applied on any one argument. You cannot have multiple arguments this way.

[00:36:38]Keep that in mind. Okay? It is on one argument only.

[00:36:44]Fine?

[00:36:45]Is this class clear for all of you students? Did you understand this now?

[00:36:49]This example?

[00:36:51]Yes, did you understand this example?

[00:36:55]Okay.

[00:36:56]Good then.

[00:36:57]Now, we're going to look at what if the method is static? Then that's straightforward. If the method was static, let's take few examples on that.

[00:37:05]That's a very simple one.

[00:37:06]Now, suppose the method was static, then in that case, you can directly call that with a class name.

[00:37:14]a dot test That's it because the method here is a static method. And since it's a static method, you keep that in mind that we guys are directly going to print now 500.

[00:37:32]Okay? Let's run this and see. Let's run this and see. It prints now what? 500. I hope this part is clear for all of you.

[00:37:42]Okay? Same way, if it is returning a value, then what would you do?

[00:37:45]Just change the return type from void to int.

[00:37:49]Since you're returning a value, return some value. Let's say 500.

[00:37:54]Suppose you don't want to print anything, then delete that line.

[00:37:58]Now, this value will be returned back to line five.

[00:38:03]Store it in the variable x.

[00:38:05]Since x is created within method, it's a local variable. Since x is created within the method, it's a local variable. Let's print x.

[00:38:13]Let's try to run this and see. It prints now 500.

[00:38:17]Is this part clear?

[00:38:20]Same way, if you want to supply multiple values.

[00:38:22]So this is a straightforward thing.

[00:38:24]Okay, you want to supply some arguments then int x, int y.

[00:38:30]Okay, int x, int y you can add that. x + y Okay, local variable names can be same.

[00:38:38]You see that here? This is x, this is also x. It can be same.

[00:38:42]10, 20 And now when I run that, observe it prints 30.

[00:38:48]Did you understand this example students? Are you able to now follow me?

[00:38:52]Yes?

[00:38:54]Everyone clear with this? Was today's class clear?

[00:38:57]Offline students, online students, classroom students, online students, I'm assuming you're all clear with that.

[00:39:04]If any doubts offline student, you can also drop a message in the chat box. You can also drop a message in the chat box, WhatsApp chat box.

[00:39:14]Offline students.

[00:39:16]And if everything clear then the next topic will be all about installation. Okay, so this is all about calling the same method several times.

[00:39:26]How many times the method will be called now? Suppose if I do this a.test, let's debug and see.

[00:39:32]Let's not supply any value to it.

[00:39:35]Let's not supply any value to it.

[00:39:37]Observe now. Let's write here again a.test. Again a.test. So what will happen now?

[00:39:44]See, the flow.

[00:39:47]Okay, I'm at line five. Let's debug.

[00:39:50]Let's debug. There's some error here.

[00:39:52]Let me resolve that error.

[00:39:54]Remove this return keyword. Make this as void.

[00:39:58]So how many times will it print now?

[00:40:01]500.

[00:40:02]How many times will it print 500?

[00:40:05]Three times. a1.test it will call 500.

[00:40:08]a.test 500. a.test 500. Three times the method is being called.

[00:40:15]Okay?

[00:40:16]Excellent.

[00:40:18]So data types you've already covered it.

[00:40:21]Right? But, we are going to discuss more about uh var type in tomorrow's class, and we will also look at how to install okay, you know, Eclipse JDK, and we will look at debugging some of the steps in tomorrow's lecture.

[00:40:41]Okay? So, we'll stop here today's lecture then. Yes?

[00:40:45]Was the audio quite clear?

[00:40:48]Payment, see, this is the number 9632629033.

[00:40:55]People, whoever is joining for the program, share the screenshot, and there are one or two people I could not add them up on Friday. I will add them up today for the recorded class, uh which we missed it. I'll ask the staff to share the Excel.

[00:41:10]You can WhatsApp this number, and they will tell you how the payment needs to be done. After the payment, please do share the screenshot with me as well as the staff.

[00:41:20]Okay? So, tomorrow, our discussion will be about Java 10 feature, var type. This was introduced in Java version 10.

[00:41:29]And we'll understand why this was introduced, and what is the purpose of var type. Okay? What is the purpose of var type?

[00:41:40]Fine?

[00:41:41]That's it then. Thank you. Bye-bye. Take care.

[00:41:44]See you again in the next class, that's tomorrow, same time. And one more thing, people who have communication skills problem, right? They have communication skills problem, and they feel that they have to improve their communication skills, then I will definitely provide, okay, you know, the solution for the same, that how one can improve their communication skills daily by doing one-to-one practicing. Okay?

[00:42:17]So, that's very much possible. I will definitely discuss about that in my further series of lecture.

[00:42:27]Now, if any old student missed my classes earlier for some reason and could not complete my classes, drop me a message personally. I will interact with you and will try to help you with the same. Okay?

[00:42:43]We'll understand that in case if you're not working anywhere, you skipped the classes, you missed the classes, you did not join our classes for some reasons.

[00:42:52]Okay, you left the course in between incomplete. Then in that case,