C#
Cart design
Design the shopping cart class skeleton and the product model.
Cart design
In this project we will build a shopping cart application step by step. The first step is to design the Product class that represents an item in the cart.
A product has three core properties: name (string), price (double) and quantity (int). In C# we write these as auto properties using public ... { get; set; }. They can then be accessed as p.Name from outside.
Auto property
In C#, writing public string Name { get; set; } creates an auto property. The compiler generates a hidden field behind the scenes; you do not write the get/set body.
This is very handy for classes that simply carry data. You can build the object shortly with var p = new Product { Name = "Pen", Price = 12.5, Quantity = 2 };; this form is called an object initializer.
Exercise Define the Product class
Define a Product class. It must have three auto properties: public string Name, public double Price, public int Quantity (each with { get; set; }). Main already builds a Product and prints its name; you only write the class.
Show example solution
Write class Product and add three auto properties inside.
Example solution:
using System;
class Product
{
public string Name { get; set; }
public double Price { get; set; }
public int Quantity { get; set; }
}
class Program
{
static void Main()
{
var p = new Product { Name = "Pen", Price = 12.5, Quantity = 2 };
Console.WriteLine(p.Name);
}
}
Test yourself
-
Which data structure fits a cart best?
// several products in a cart
- A single int variable
- A single string variable
- A list holding Product objects
- A bool variable
Show answer
A list holding Product objects — Correct. You hold several Product objects in a List<Product>.
-
Write the class name
class ____
{
public string Name { get; set; }
public double Price { get; set; }
public int Quantity { get; set; }
}
Show answer
class Product
{
public string Name { get; set; }
public double Price { get; set; }
public int Quantity { get; set; }
}
-
Match each property name to its type
- Name
- string
- Price
- double
- Quantity
- int
- items
- List<Product>
Next lesson: Adding products
