Classes, Object Instances and Constructor Methods in C # and Microsoft Visual Studio!

what's going on guys welcome back to the channel and today's video is going to be all about classes objects and constructors in c-sharp using visual studio [Music] so this is a continuation in our c-sharp tutorial series um and i just want to say real quick thank you to everyone who has suggested topics for videos asked for help in the comments and left likes on the videos and subscribe to the channel it's helping me a ton just getting this channel started so to continue on in our c-sharp tutorial series we've talked about basic variable types and we've talked about for loops and while loops and some basic things you can do with code but one thing we haven't talked about yet is what do you do when you have a more advanced variable type so we've talked about just how to create a variable that's a string like a name or or something along those lines um you know and and that's fine but you get things sometimes in code that need to have multiple attributes assigned to them and essentially you want to group those attributes together and create a new data type that is essentially a class in c sharp and the way you make it is pretty easy and the way you use it is pretty easy so we're going to go ahead and take a look at that today and i want to do it kind of in a fun way so i want to do it by acting like we're creating a class for storing video game information so let's say you come over to your solution explorer right click on your c sharp file and then go down to add and then go to new item and it should give you this pop-up and pretty much always right near the top is going to be class but you can search in here if it's not and just go ahead and hit add class and it's going to auto-generate pretty similar to when you open up your initial program and to get between the two you just click these tabs at the top here but okay so what we do inside of this class is we define the attributes that we want in the outside world so if you think of a few things you would want to store in like a video game storage class you'd want like the title of the game and so if this were in the outside world you would do this you would just say okay string title and then equals whatever because you're defining it but here we're actually saying we want to be like a generic variable that can be called by the outside world so we need to add this public before it and then we just do a semicolon right there and we don't actually give it any initial value because you don't set those variables equal to any value when you define the class unless you want to give them a default value they get set when you create a class in the outside world so i'm going to copy that and let's say a second thing we want for the studio um or for the video game like definition to store the information about is what studio produced it and then let's use a double which if you remember from our variable types is just a precise number it's like a float or a decimal value that can do more accurate than integers and we'll give it a rating like out of five stars and then we'll do just one more so that i can show these classes can handle data from various different data types so that's the really the power of using it is you can use strings doubles ins you can put functions inside of these and methods that we'll talk about as well but then we'll say okay what year was it made and for now i think we'll just leave it at this and maybe so that you can see what's happening when we go back to our function we'll come back to this but let's just leave it here for now because we've really just created it but the thing we haven't done is we just called it class one and actually typically when you're making this i recommend giving it a name that's going to be a little bit easier to um to know what's in there so when you create it there's an option to rename it but you also can rename it just within your game and you can see there just going down into file name you can rename it and just make sure you also call the class whatever you name the file so we'll call ours game and let's go back into the program and actually make a couple of these okay so the way you create a new instance of the class that you just made and this is what's considered an object is an instance of a class it's very similar to defining a new variable you say game so that's the class that we're calling and then just your variable name and we'll call it game one but you can call it whatever you want it's a variable name and then you say equals new and then game and then just open close brackets and we'll talk about you can pass arguments in there and we'll do that in just a second but now what we can do is like okay we've made the game so if i type in game one dot you get all of these variables that it knows because it can see your class it knows to expect year studio title rating and so we can go in here and we can give it that information we can say game one title equals halo we can say the studio i'll try not to mess these up the studio is real halo fans know the studio is uh bungee if you type 343 in here you're too young get out and then we'll give it a rating so this is like how good we thought the game was out of 5 stars we'll say 4.5 it's a good game and what year it released so halo 1 the original one 2001 but what's really cool is okay we've just created all of this stuff and so if i do something here if i do console.rt and then i tell them we want to see game1.title okay when i run this function it should just print out halo onto the screen because even though we didn't create the class in this function it's in our program and we referenced it so i'll just go ahead and run it and we'll see halo okay we got that that's nice it's not really too exciting right now but where it becomes really powerful is you can take what we just did and you can change it all to game two and you can put a second game in there and have all the same driver code class code behind it so let's say this is super mario and that was made by nintendo and let's give that a rating of 4.0 and that came out in 1983 okay and so now if i were to say game one title i can also say game two title and what you'll see is we get both titles and that's great you know that's the basics of a class and how to create one and how to create objects under a class but where this becomes way more powerful is you get to really start cleaning up this code when you use what's called a constructor and let's go ahead and do that next so coming back into our class here we're going to keep all of this just as is but we're going to create something that's called a constructor and so to do that we're going to say public and then the name of the class again game and then we're going to give it open and close parentheses and then we're going to tell it what sort of arguments to expect so what i want is i want from this line i want to be able to just give it right here in these parentheses the title the studio the rating and the year and not have to have these four lines of code in here and so we come in here and we say okay we're going to pass in the title but we don't just say string title like we would in the outside world because title already exists in this class so what you need to do is you need to give it a different name so i'll say arg title short for argument title you can call it whatever you want the thing is you can't use exactly the same name that you already used in defining your class it'll make a little more sense as soon as we get to the next part but then let's say the second thing is string we need the studio next will be double and we need the r grading and then the last one is int and we'll want the r gear okay and now i'll be able to show you a little bit better why we had to do it that way so if we come down here we need to well we need the container for this code we need to take those argument variables and assign them to the internal variables of the class so we've already defined title so what we do is we say title is equal to arg title and then we do that for every one of them we say studio is equal to arg studio and this may seem like kind of a extra step of tying stuff together but it's really not because what we did when we said um title studio rating and year is we said what their internal names are going to be but then these are the parameters that are actually being passed in so i mean these could be totally meaningless as long as you tie them to the right thing and you know what you're tying them to when you define them it's fine but it's just a better idea to give them a name that's going to make it more clear what you're doing okay so you want it to look like this you want all of your your variables you're passing in to be mapped to um to be mapped to internal variables and to kind of show that this runs every time we call a object i'm going to do one thing as well i'm going to say console.writeline and i'm going to print this storing data for and then i'm going to also say the title of the game and then just because it looks a little better i'm going to add a new line character so basically every time we make a new game it'll print out on the console storing data for whatever game we're making and then print an empty line just to separate out these different things that are happening okay so this is super cool go ahead and save it and head back into the main program what we can do now is we can get rid of these lines of code and i'll show you how because we have this constructor and it's giving us a red line it should be giving you a red line because now it's expecting parameters passed in so now we give it a title halo and we give it a studio bungie and we give it its rating and then we give it the year it came out okay and we can get rid of all four of these and we do this same thing down here super mario nintendo 4.0 1983. okay and now we get rid of these four lines of code so you can see just doing that we just went from 10 lines of code to two lines of code and so now i'll do the same thing i'll show the game one title but what i want to make clear here as well is actually we're not going to do title because we're going to show the title um we'll we'll do this this will be kind of cool we'll say um game game one not with a capital g game one dot title and then we'll add to it was made by and then we'll add game one dot studio and then we'll add in and then last thing we'll add gameone.year okay so i just want to show that even though we never say here what variable type title is we don't say that this is going to be title that's all being handled in the class over here and then what we'll do is we'll say game2 dot rating is equal to 4.3 just because i also want to show you can update those parameters even after they're initially created so that's what we're doing here and so then we'll say here game two rating and we'll actually say game two dot title and we'll add has a rating of and then we'll add the rating so even though when we define super mario brothers we gave it a rating of 4.0 during our function we decided to update the rating to 4.3 okay so let's go ahead and just run this because i know we did a lot of stuff we haven't run in a little while so you'll see storing data for halo storing data for super mario i guess i put an extra caps in there but these first two are happening in the class in the ca in the uh class that we defined separately but then these next ones are happening in our main project um so these top two are happening because of the constructor function that we made but then we're using that data and manipulate manipulating it wow so halo was made by bungie in 2001 super mario's rating of 4.3 so maybe using games is a bit of a silly example but i think there's a really quick and really useful introduction to classes objects and constructors in c sharp we're cut we've covered a lot of the basic building blocks of various c-sharp programs of building more advanced c-sharp programs and so what some of the upcoming tutorials will be are actually your first application you could build with a graphical user interface or how this might apply to plugging into like a game engine like unity how c-sharp can be leveraged there so we will be diving into some of those concepts if there are more basic concepts that you would like to see and see sharp before we get into too much of the advanced stuff just let me know about in the comments below um if there's enough interest in a topic i'll be sure to make a video on it if you have found these useful please consider subscribing to the channel leaving a like on the video it helps me out a ton i really appreciate all of the support and as always good luck with your code and thanks for watching thanks bye