GroupBy operation in C Sharp (C#) - Mini Project: Build & Apply

GroupBy operation

📖 Scenario: You work in a small store. You have a list of sales records. Each record has a Product name and a Quantity sold.You want to group these sales by product to see how many units of each product were sold in total.

🎯 Goal: Build a program that groups sales by product name and sums the quantities for each product.

📋 What You'll Learn

Create a list of sales records with exact products and quantities

Create a variable to hold the grouped sales result

Use LINQ GroupBy to group sales by product

Sum the quantities for each product group

Print the product name and total quantity sold for each group

💡 Why This Matters

🌍 Real World

Grouping sales data by product helps stores understand which products sell the most and manage inventory better.

💼 Career

Data grouping and aggregation are common tasks in software development, especially in reporting, analytics, and business intelligence roles.

1

Create the sales data list

Create a list called sales of Sale objects with these exact entries: new Sale("Apple", 10), new Sale("Banana", 5), new Sale("Apple", 7), new Sale("Orange", 3), new Sale("Banana", 2). Also define the Sale class with public properties Product (string) and Quantity (int).

C Sharp (C#)

// Define Sale class and create sales list
// Your code here

Need a hint?

Define the Sale class first. Then create a List<Sale> called sales with the exact entries.

2

Create a variable for grouped sales

Add a variable called groupedSales of type var to hold the grouped sales result. Initialize it to null for now.

C Sharp (C#)

using System;
using System.Collections.Generic;

public class Sale
{
    public string Product { get; set; }
    public int Quantity { get; set; }

    public Sale(string product, int quantity)
    {
        Product = product;
        Quantity = quantity;
    }
}

class Program
{
    static void Main()
    {
        List sales = new List
        {
            new Sale("Apple", 10),
            new Sale("Banana", 5),
            new Sale("Apple", 7),
            new Sale("Orange", 3),
            new Sale("Banana", 2)
        };
        var groupedSales = null;
        // Your code here
    }
}

Need a hint?

Use sales.GroupBy(sale => sale.Product) to group sales by product.

3

Sum quantities for each product group

Change the groupedSales variable to hold the result of grouping sales by Product and summing the Quantity for each group. Use LINQ GroupBy and Select to create an anonymous type with Product and TotalQuantity.

C Sharp (C#)

using System;
using System.Collections.Generic;
using System.Linq;

public class Sale
{
    public string Product { get; set; }
    public int Quantity { get; set; }

    public Sale(string product, int quantity)
    {
        Product = product;
        Quantity = quantity;
    }
}

class Program
{
    static void Main()
    {
        List sales = new List
        {
            new Sale("Apple", 10),
            new Sale("Banana", 5),
            new Sale("Apple", 7),
            new Sale("Orange", 3),
            new Sale("Banana", 2)
        };
        var groupedSales = sales.GroupBy(sale => sale.Product);
        // Use GroupBy and Select to sum quantities
        // Your code here
    }
}

Need a hint?

Use Select after GroupBy to create a new object with Product and the sum of Quantity.

4

Print the grouped sales totals

Use a foreach loop to print each product and its total quantity from groupedSales. Use Console.WriteLine with the format: "Product: {product}, Total Quantity: {total}".

C Sharp (C#)

using System;
using System.Collections.Generic;
using System.Linq;

public class Sale
{
    public string Product { get; set; }
    public int Quantity { get; set; }

    public Sale(string product, int quantity)
    {
        Product = product;
        Quantity = quantity;
    }
}

class Program
{
    static void Main()
    {
        List sales = new List
        {
            new Sale("Apple", 10),
            new Sale("Banana", 5),
            new Sale("Apple", 7),
            new Sale("Orange", 3),
            new Sale("Banana", 2)
        };
        var groupedSales = sales.GroupBy(sale => sale.Product)
            .Select(group => new
            {
                Product = group.Key,
                TotalQuantity = group.Sum(sale => sale.Quantity)
            });
        foreach (var group in groupedSales)
        {
            // Print product and total quantity
            // Your code here
        }
    }
}

Need a hint?

Use a foreach loop to print each group's product and total quantity using Console.WriteLine and string interpolation.