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Hey, welcome back, kid.

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I know the last lesson was fairly lengthy in this lesson, I'm going to try to keep it short and I do

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apologize for the last one.

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This lesson we are going to be looking at prototype in JavaScript.

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So object prototype is a property of an object constructor and it's also the end of a prototype chain.

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So all JavaScript objects inherit properties and methods from the prototype.

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So this gives you the ability to add to a particular object and add additional functionality and methods

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to those objects.

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And of course, you have to declare it before you try to use it.

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And objects such as the DETE object so you can update and date prototype can inherit within the date

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object, so you can use existing ones as well as create your own.

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And there's an example of this and there's more information about prototype, of course, at the Mozilla

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Developer Network.

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So more information about just different ways to create prototypes, said work with prototypes.

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They've got an example here.

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So object prototype value of so this is extending on value of and adding in different functionality

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to those so you can use those and utilize them.

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So they've got an example here of the person and updating that prototype with greet.

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So now when you call to person, so using it as an object, you can extend on that person and have a

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greeting coming back.

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So let me show you a little bit more, opening up the editor.

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Let's create our first function and we can call this one just person.

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So we've got first and last as parameters that are coming into the function.

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And then we're using this first name is going to be equal to whatever the value of first is in this

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last name is going to be equal to whatever the value of last is.

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So it's going to be a quick and easy way to create an object and then we're going to extend on that

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person prototype.

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So if we create a new object and we could just call it meat and we can use new person, so extending

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on that object that we have, we can pass in the first name as well as the last name that we can use

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in the object if we consult, like about me.

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What do you think is going to happen?

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You're going to see that we've got person and we've got first name, last name so we can use that.

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So let's create a prototype on person so that a person object and using prototype, we're extending

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on that.

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So we're going to add in a method called full name and function.

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So it's going to be a method where it's going to use the values are contained within the object.

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So seeking this and it's taking this first name value and adding with space in the middle last name,

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and that's what's going to return back as the prototype.

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So now that gives me the ability.

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So if I save that and I'm simply outputting it as an object into the console, but now if I do console,

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log me full name or simply just call back to see full name.

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So I'm using the prototype and it's returning back by fullName that have passed on from the object that

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was created.

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So there is a challenge to this lesson and we did mention that the date object in JavaScript, so you

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can add a prototype to it.

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So extending on a date where you can have the date method and then you can simply add days to it.

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So the objective is to create a prototype on the date object where you can add days to it specifying

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a parameter that comes in.

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And this is the number of days that get added.

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And so go ahead and try this out and I'll walk you through the solutions.

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You can pause the video here and I'll walk you through the solution.

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This could be a really short solution.

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So taking our DETE prototype, so the date object, because that exists in JavaScript and then using

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prototype to extend on it, we're creating a method called add days and then setting that up as a function.

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So it's taking in a parameter of days and it's going to take that and make a calculation.

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So new Dete, it's going to take the current value of and then add days to it.

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We're going to multiply this.

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So this is eighty six for E five.

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So that should give us the amount of milliseconds in the days and basically allowing us to make that

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calculation.

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So now if we do console log and the nice thing about prototype is you can use it over and over again

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so we can add days to it and we can specify how many days we want to add in to the date so that when

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we refresh it, we see we automatically add seven days into the current date.

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Today is the third.

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We're coming back at the tenth.

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If I add seventeen and so we can do 20, we can do a hundred and whatever we want to do.

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So just save that.

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Refresh that.

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So that's coming into July 18th and we can even out a thousand.

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So refresh going up to 20, 22 and so on.

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So coming up next is try and catch such a very interesting one that you can utilize in JavaScript.