How can I use LINQ to group data in C#?

How can I use LINQ to group data in C#?

You can use the GroupBy method in LINQ to group data based on a specific key. For example, if you have a list of products and you want to group them by category, you can do it like this:

var groupedProducts = products.GroupBy(p => p.Category);

Can you show me a complete example with a list of products?

Sure! Here's a complete example:

var products = new List<Product>
{
    new Product { Name = "Apple", Category = "Fruits" },
    new Product { Name = "Banana", Category = "Fruits" },
    new Product { Name = "Carrot", Category = "Vegetables" }
};

var groupedProducts = products.GroupBy(p => p.Category);

foreach (var group in groupedProducts)
{
    Console.WriteLine($"Category: {group.Key}");
    foreach (var product in group)
    {
        Console.WriteLine($" - {product.Name}");
    }
}

What if I want to count the number of products in each category?

You can use the Select method after grouping to project the results. Here's how you can count the products:

var productCounts = products.GroupBy(p => p.Category)
                            .Select(g => new { Category = g.Key, Count = g.Count() });

foreach (var item in productCounts)
{
    Console.WriteLine($"Category: {item.Category}, Count: {item.Count}");
}