Hello, all welcome back to the next one. So in the last class, we talked about methods, and we kinda understood what the method is. And we talked about the main method, which is the entry point of the class. And we saw an example that if we do not have a main method, the class doesn't run, right. So now let's move forward, I created one more class inside our Opie concepts package. And I named it as adding methods.

I'm just putting the name randomly, but I'm just gonna add few more methods to this one. We talked about that a class can have multiple methods, and we'll see how it makes sense. And why do we need multiple methods and what do we do with them. We will also talk about this wide and we will come up with one more return type. I'm going to talk about that. So let's do that.

So I created a main method inside this class. And there's a very simple code What it does is currently, I just have a string variable called student name, and I provided the value as john. The score I have given right now here is 90, there's a variable called grade, and that's also a string. And by now you might have the idea already. So what we are trying to do here is if the score is between 90 to 100, we are giving a, if it's between 80 to 90, we are giving B. If it's between 70 to 80, we are giving C and otherwise D. Obviously, we're not covering all the possible scenarios because we are not writing a code for a grade generator.

If somebody gives a score greater than hundred here, it's gonna fail and we know that what we're trying to do here is we're trying to understand the concept of methods right. And then finally, we are printing the grade of the student and the student name which is going to come From this variable, and grade is going to be calculated in this if else condition. So this is our simple main method. Let's just run it and see the output. So the output is create of john is a, which is all good. Now, let's say that I want to find the grade of another student.

And the name of the student is maybe something else. And I want to keep this also right. So what can I do like I can either copy this code and put it like this. And maybe I can just say name of the student is Tom. And since this is variable is already defined, I can remove the declaration and only put the values so I can do this. And then again, I can print a new score.

Maybe I can give us core value as Eri or something and then do this. So this is our alternative right now like this is what we will do if we are writing in the main method everything. This is how will work, right? So this is for the first student, I want to write for the second student, I'll provide a new value to the second student. Let me just bring it up. So that actually, yeah, I just want to bring it up so that we have a little bit of viewing space above it.

Yeah. So we will provide another name, we will provide another score, and then we can calculate the credit, right? And if I want for, like, 10 students, I'd have to repeat everything. I'll have to put this code again, I'll have to copy everything and then find those things. Right. Does that look like a meaningful programming?

Like, what are we achieving? We're for a simple thing we're writing like, thousand lines of code, maybe if we have. So let's imagine like currently I have about 30 or maybe like 11 lines of code for one store, and I have like 100 students, I'm already like writing 1100 lines of code. This doesn't look efficient to me. So and obviously to most of you. So, what we're gonna do here is we're gonna come up with methods, and we're gonna write a separate methods.

So if we understand the methods, what we talked about is a method of way to do something. What we're trying to do here is we're trying to find the grade and we are printing, the student got this much great. So if somehow we put this logic somewhere, and if it can do the thing for us, like that method or that function, you can call it can do the stuff for us, then it will make sense and we can utilize that method again and again, to achieve our desired functionality. So this is what we can achieve here. So let me just delete this thing. We don't need this Let me do one thing.

This block is the main method. Let me just hit Enter. And I'm going to create another method name. And I'm going to call it like public, static, wide. And let's name it maybe like grades, fine grades. And for now, I'm just gonna copy complete code into this method.

And slowly we'll see the advantages. So now, what I can do here is I can copy the I can call this. So if the method is static, we can actually call it directly and don't worry about when I'm saying static or something, we do have a completely different section about static. So you will understand everything there. But for now, we can just call the methods directly directly into another method. So I'm just going to call find grades here.

And we saw that if we don't call the methods in the main method, then it's not gonna work because main method is the entry point. So we have to call any method here. So now let's just make this part work. And then we'll see the remaining stuff. So yeah, I want to save this file. And we can see at the bottom, the grade of john is a still we are seeing the correct result.

But have we solved the purpose? We haven't tried. Instead of putting it here, we have put this thing there. How do we want to solve it? The first thing we want to do here is these methods can actually accept arguments. And we can make them to accept the kind of data that we want and then that data can be manipulated inside the methods.

So what I can do here is, I can say that I want this method to accept the name. So maybe the name of the student let's say student name and What else do I want? I want the score of the student right. So this is these are the two things that I want to provide from outside. And I want to give Okay, I have a name of the student. My name is john, he got 90 marks, please give me his grades, right?

I have another student called Tom, he got 80 marks, please give me his grades. So these are the two things I want to provide to this method. And I want to fetch the output of grades. So now let's call it like string. Or not string score is integer. So we want to provide the data type is related to what we're going to get.

So score is integer score is actually an integer value, right? And all the arguments are separated by comma. You can give any number of arguments there's no limit. This is the data type again, and this is the variable name. And now we start seeing errors here and it says duplicate local variable student name. So since we already know Find it here that this method is going to accept a string variable student and an integer variable called score.

Java kind of creates a local variable with these names automatically, so we don't have to define them again, what we can do here is we can delete them. And we don't even want these values, right? Because what we are trying to do here is we're trying to call this method and from outside we will provide these values, so we can just simply get rid of it. That's it boom. Now, this is giving me errors. What does it say?

It says that method, the method find grades, string, comma int, which means it accepts two arguments, one of type string, another of type end. In the type, adding methods the type adding methods means the class name, that type is adding methods. So class name is always also a data type. It's the type of the object is not happening. table for the arguments, empty parentheses. As you can see, they're empty parenthesis because here they are empty.

So what's happening here is now it kind of accepts two arguments, it requires them it needs those two arguments, but they are not giving anything. So what we can do here is, we can give the arguments here, let's say john, and score is 90. This is kind of a thing that we want to do, and we'll do furthermore. So now, if I run my code, what's gonna happen here it's gonna print the same output, trade off john is pay. And we can see that we provided the variable from here. And the greatest define here and everything works smoothly.

So this john came to student name and this 90 came to score. That's how Java works. Now the benefit is, if I have 100 students, I only had hundred lines, not 1100. I can say Tom here And I can see maybe 80. And let's run the code again. So if I run the code again, run as Java application, I see two outputs, grade of john is a and grade of Thomas be all set and done.

So what we did is we created a method up here. And now we are utilizing this method here, right? That's pretty cool. And we kind of reduced that redundancy kind of thing that's happening. And we made this code a little bit efficient, right. So that's about it.

For now. Please download the score, practice this quarter little bit, how to run and try to change the values. And in the next lecture, I'll show one more small concept. And then we're kind of good bed methods. So stay tuned for the next lectures, and thanks for attending this one. Thanks, guys.