Here are the assignments for All 5 Platforms

You will develop 2 mobile apps:
1) Practice: An app the reads the radius and creates a circle object to calculate the area and circumference of the circle. I will give you an example of this for each chapter.
2) Assignment: An app that reads the length and width and creates a rectangle object to calculate the area and perimeter of the rectangle. Note you will add another textbox (input) control and create a constructor that take two parameters. 

Examples of constructors that take 2 parameters:

JavaScript:

    var myRect = new Rectangle(len,wid);

    //Rectangle.js

    constructor(len,wid)

    {

  this.length=len;

          this.width=wid;

    }

Java:

    Rectangle myRect = new Rectangle(l,w);

    //Rectangle.java

    public Rectangle(double length, double width)

    {

        this.length = length;

        this.width = width;

    }

C#:

    Rectangle myRect = new Rectangle (Double.Parse(etLength.Text),Double.Parse(etWidth.Text) );

    //Rectangle.cs

    public Rectangle (double length, double width)

   {

            this.length  = length;

            this.width  = width;

    }

Swift:

     let myRect=Rectangle(length:len!, width:wid! );

    //Rectangle.swift

     init(length: Double, width: Double) { // Constructor

        self.length= length

        self.width=width        

     }

You will implement the assignments on the following platforms:

• MIT AppInventor
• Android and Android studio, language is java.
• Xamarin and Microsoft Visual Studio. lamguage is C#. 
• iOS and Xcode , the language is Swift.
• Cross Platform Web: with a code editor (replit.com is preferred), the language is HTML5, CSS and Javascript.