This course is for JavaScript developers who are preparing for their interviews and want to learn about the types of design patterns. The course is divided into four sections, each explaining one category of the design pattern. The types covered in this course include creational, structural, behavioral, and architectural design patterns. Each pattern is explained with the help of examples and is followed by a challenge and its solution review.

Acing the JavaScript Design Patterns Interview

## Problem statement

In this challenge, you need to implement sending and displaying a sent email using the MVP pattern. You have already been given the dummy code for the classes you need to implement.

In the `Model` class should contain the following:

* The properties: sender's name, receiver's name, and the email title.

* The get and set functions to access and set the values of each property.

In the `View` class, you need to do the following:

* Define the `sendEmail` function to send an email.

In the `Presenter` class, you need to do the following:

* Define the `setModel` function that sets the model.

* Define the `getView` function to return the view.

* Define the `sendEmail` function that sets the properties of the email and displays the email information.

## Input

The `sendEmail` function is called

## Output

The information of the email is displayed 

## Sample input

```
var model   = new Model()
var view = new View()
var presenter = new Presenter(view)
presenter.setModel(model)
view.registerWith(presenter)
presenter.getView().sendEmail("Rachel", "Joey", "Rent Discussion")
presenter.getView().sendEmail("Monica", "Phoebe", "Smelly Cat Draft")
```

## Sample output

```
"Email From: Joey To: Rachel Title: Rent Discussion"

"Email From: Phoebe To: Monica Title: Smelly Cat Draft"
```

## Challenge 
Take a close look and design a step-by-step solution before jumping on to the implementation. This problem is designed for your practice, so try to solve it on your own first. If you get stuck, you can always refer to the solution provided. Good Luck!

class Model{
    //write your code here
}

class View{
    constructor(){
        this.presenter = null;
    }

    registerWith(presenter){
        this.presenter = presenter;
    }

    sendEmail(to,fromWhom, emailTitle){
        //write code here
    }

    displayEmailInfo(senderName,recieverName, emailTitle){
        console.log("Email From: "  + senderName + " To: " + recieverName + " Title: " + emailTitle);
    }

}

class Presenter{
    constructor(view){
        this.view = view;
        this.model = null;
    }

    setModel(model){
        //write code here
    }

    getView(){
       //write code here
    }

    sendEmail(to,fromWhom, emailTitle){
        //write your code here
    }
}

class Model{

    constructor(){
        this.senderName = "";
        this.recieverName = "";
        this.emailTitle = "";
    }

    setSenderName(senderName){
        this.senderName = senderName;
    }

    getSenderName(){
        return this.senderName;
    }

    setRecieverName(recieverName){
        this.recieverName = recieverName;
    }

    getRecieverName(){
        return this.recieverName;
    }

    setEmailTitle(emailTitle){
        this.emailTitle = emailTitle;
    }

    getEmailTitle(){
        return this.emailTitle;
    }

}

class View{
    constructor(){
        this.presenter = null;
    }

    registerWith(presenter){
        this.presenter = presenter;
    }

    sendEmail(to,fromWhom, emailTitle){
        this.presenter.sendEmail(to,fromWhom, emailTitle)
    }

    displayEmailInfo(senderName,recieverName, emailTitle){
        console.log("Email From: "  + senderName + " To: " + recieverName + " Title: " + emailTitle);
    }

}

class Presenter{
    constructor(view){
        this.view = view;
        this.model = null;
    }

    setModel(model){
        this.model= model;
    }

    getView(){
        return this.view;
    }

    sendEmail(to,fromWhom, emailTitle){
        this.model.setEmailTitle(emailTitle)
        this.model.setSenderName(fromWhom)
        this.model.setRecieverName(to)
        this.view.displayEmailInfo(this.model.getSenderName(), this.model.getRecieverName(),this.model.getEmailTitle())
    }
}

-----
Let’s discuss the solution in the next lesson.

# Problem statement

In this challenge, you need to implement sending and displaying a sent email using the MVP pattern. You have already been given the dummy code for the classes you need to implement.

In the `Model` class should contain the following:

* The properties: sender's name, receiver's name, and the email title.

* The get and set functions to access and set the values of each property.

In the `View` class, you need to do the following:

* Define the `sendEmail` function to send an email.

In the `Presenter` class, you need to do the following:

* Define the `setModel` function that sets the model.

* Define the `getView` function to return the view.

* Define the `sendEmail` function that sets the properties of the email and displays the email information.

# Input

The `sendEmail` function is called

# Output

The information of the email is displayed 

# Sample input

```
var model   = new Model()
var view = new View()
var presenter = new Presenter(view)
presenter.setModel(model)
view.registerWith(presenter)
presenter.getView().sendEmail("Rachel", "Joey", "Rent Discussion")
presenter.getView().sendEmail("Monica", "Phoebe", "Smelly Cat Draft")
```

# Sample output

```
"Email From: Joey To: Rachel Title: Rent Discussion"

"Email From: Phoebe To: Monica Title: Smelly Cat Draft"
```

# Challenge 
Take a close look and design a step-by-step solution before jumping on to the implementation. This problem is designed for your practice, so try to solve it on your own first. If you get stuck, you can always refer to the solution provided. Good Luck!

In this challenge, you have to implement the MVP pattern to solve the given problem.

Challenge: MVP Pattern

Problem statement

Input

Output

Sample input

Sample output

Challenge #