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‫And this video, we are going to look at the parents keyword that you might have come across or maybe

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‫not, but it's definitely something that is very useful when programming and it's going to be very important

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‫for your arsenal of features that you can control in C-sharp development.

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‫So let's look at it.

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‫The thing is, we have used methods that use params already, and I can tell you that because we have

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‫used right line quite a bit and right line, as you see here, says hello world.

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‫Well, the cool thing is if you check out the right line like so you hover over it and then you can

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‫see that it has multiple overloads.

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‫So basically let me type it in here once again, right line like so.

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‫And then once I open the bracket, it shows that there are 18 different overloads.

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‫Overloads are basically different kind of implementations for this method.

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‫So there is not just one implementation for this method inside of the console class, but there are

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‫multiple ones.

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‫So you can check it out here by clicking into it.

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‫You can see there are a bunch of right line implementations here.

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‫So the simple one, then the one that takes a boolean value, the one that takes the buffer for well,

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‫basically a set of characters and so forth.

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‫So there are a bunch of different overloads that this bright line has.

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‫And the one that I am referring to in particular is going to be the one that we have here.

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‫So it's the 15th one, at least in my version of Visual Studio.

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‫This might change depending on when you check it out.

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‫And you can see here there is this params keyword, so it says params object array arg.

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‫So this means that it will accept as many parameters as you give it and it will accept parameters of

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‫type object.

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‫Basically, every single class element that you create or every single one, basically objects of anything

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‫is going to be of that type object.

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‫So even this class program internally is going to inherit from object.

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‫We're going to look at inheritance a little later, but basically it just says it accepts any type of

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‫information or any type of data.

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‫So that's really the cool thing about this particular example, but you don't have to use it in a way

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‫that it accepts any type of information.

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‫So before we get too complicated, let's just actually see an example.

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‫So we saw in this overload that it accepts a string format and then the parameters later.

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‫So let's just pass a couple of values to this right line method.

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‫So we're just going to use price is and then whatever the value or the first value that we have after

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‫this string and a comma that we pass as a parameter is going to be so it will be this position zero.

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‫Then PI is 314 which is going to be at this position and ET is and this is going to be this ad sign.

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‫So if we run this.

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‫You will see that it basically accepted all of our parameters.

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‫So it just price is 32, pi is 3.148 is the ADD sign.

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‫So we could, of course, also add as many numbers as we wanted or as many parameters as we wanted.

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‫So let's have this stupid example where we are just passing the numbers like so, so one plus two plus

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‫three and so forth.

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‫Basically, these are the values that we have here, but if you want to use them in the string, we

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‫need to start with zero.

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‫So this will be the zero position, which just means that it will display the one, the second one will

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‫display the two, which will be this one here and so forth.

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‫So if we run this code, you will see that it still works.

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‫So it says one plus two plus three and so forth, until it then gives us a 28.

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‫So you see we don't have an eight here.

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‫We have a nine.

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‫We have done all of those together, which is the 28 here.

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‫So you see here we even have a calculation that we're passing to it.

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‫So it accepts all kind of stuff.

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‫But the important part that we wanted to look at are not the objects, but we are looking at the params

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‫keyword.

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‫So let's create our own example where we are going to use the params keyword in order to allow as many

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‫parameters as the colour of the method wants to throw at us.

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‫So let's create a new method, public static.

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‫We make it static so that we can use it inside of our main method, or we can call it from our main

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‫method and I'm going to return nothing and it will be of type while we will give it a name of params

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‫method.

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‫And here we're going to use this params keyword.

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‫And then it will be, in our case, not an object type, but it will be an array of strings that we

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‫can pass to it.

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‫And I'm going to call this.

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‫Array of strings sentence.

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‫So inside of our parents method.

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‫Now, what we're going to do is we're going to use a four loop.

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‫And I is going to be zero.

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‫I is going to be less than the length of the sentence.

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‫And then we increment by one.

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‫So a plus plus year.

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‫Okay.

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‫So what is it that I want to do in this loop?

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‫Well, basically, I just want to write every single item of that parameters list that was thrown at

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‫me.

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‫I want to write it onto the console and I can just do it using the console.

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‫Thought right statement here.

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‫So.

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‫Right.

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‫Using the sentence at the position of I because sentence, if you look at it is an array, it's an array

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‫of strings.

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‫So the position I will at the beginning be zero.

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‫So whatever the first parameter is that was given to me as something that I'm going to write at this

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‫point and then I will add an empty space like so.

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‫And go to the next iteration of the for loop.

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‫So this for loop now will iterate as many times as we pass parameters to this params method.

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‫So let's look at it in our main method.

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‫Let's call this method actually.

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‫So here I'm just going to call this params method with a super simple or stupid sentence, but the sentence

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‫will be broken down into individual words.

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‫So I'm just going to say this is a long string.

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‫I have no idea when it's going to end.

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‫Dot, dot, dot.

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‫And we could go to keep going at this point.

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‫But basically we're just passing one string, another string, another string and so forth.

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‫We're passing a bunch of strings here.

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‫So let's run this application.

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‫And we can see this is a long string.

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‫I have no idea when it's going to end.

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‫We could now change this at any time.

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‫So let's do it.

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‫Let's run it again.

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‫And now you see, we have crippled our sentence.

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‫This is a no idea when it's going to end, but the code still works.

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‫So the sperms keyboard basically just allows us to pass as many parameters as we want.

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‫We could have also passed no parameters at all.

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‫So let's pass no parameters.

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‫And we will see that nothing happens.

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‫But our code doesn't crash either.

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‫Okay.

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‫So that's the cool thing about this params keyword.

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‫Now let's create a method that will allow objects as well.

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‫So let's create another params method.

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‫This one will be parents method two and it will not take strings, but it will just take objects and

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‫we call it stuff.

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‫So whatever stuff we give to it, what we're going to do now is we're going to use this for each loop

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‫which will go through the stuff that we pass to it, which is an array of objects.

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‫And for every single object, it's going to put that object into the right statement here.

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‫Now what?

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‫The cool thing is, every single class has internally a method called to string.

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‫So every single class, no matter which class you create it internally, has this method or is inheriting

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‫from object, which means that it has this method called.

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‫To string.

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‫So that means that whatever object you give to our method, it will be able to make a string out of

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‫it.

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‫Even if the string will just be something like this is a class or this is the class called so-and-so.

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‫So it might not be any useful information that you get there, but it will at least make it a string

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‫and the application will not crash.

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‫So as I said, inheritance is something we are going to cover later on.

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‫Basically, it's the relationship between different classes and one class is going to be the parent.

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‫And then you have well, you can have multiple children to this class and basically the parent has a

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‫certain feature set for certain functions and members in general and the inheriting classes, they will

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‫have the same features as the parent, so the same members as the parent, but they can extend later

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‫on.

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‫But as I said, we're going to cover this in depth in a separate chapter.

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‫So here, if we run this well, nothing happens.

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‫So let's actually make this run.

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‫Let's call the parents method too, with some cool values that we're going to pass to it.

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‫Therefore, I'm going to pass it some stupid values.

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‫Let's just do it like this.

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‫Okay, so here I have an integer which I will call price, and I'm giving it the value of 50.

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‫Then I'm passing a float which will be my pi.

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‫Then I have a character which will be the ad sign.

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‫Then I have a string called book, which will be The Hobbit.

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‫And what I do now is I just go ahead and use this method to which accept it a parameters list of objects,

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‫however many it is, and we're just passing four because we decided to.

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‫We could have passed three or seven or however many we wanted, and now we're just passing all of those

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‫different variables.

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‫So we are passing the price high at and book.

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‫And if we run this now.

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‫We will see that it says 53.14 AD and The Hobbit.

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‫And then and the second line, what we call Paramount's method method two.

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‫Once again, we are just passing values directly.

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‫So we're passing a string here, a 55.3 and then a character dollar sign.

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‫So a character, it is because we're using the single quotes here.

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‫Or basically the apostrophes.

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‫So now you might wonder, why would I care about this feature?

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‫Because you gave me some examples here, Dennis, but they're not really useful to me, so why would

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‫I care?

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‫Because I can define specifically how many parameter, how many parameters I want to pass to you, and

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‫then I can be very specific about it.

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‫Well, the thing is, there are plenty of applications where that's not the case, where you will actually

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‫need to make sure that you allow the freedom of passing multiple different values.

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‫And we're going to look at it well at in a specific example in the next video.

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‫So see you there.