C# Linq count

Last modified: July 03, 2021
class Stock { public string Sku { get; set; } public string ModelName { get; set; } public string Category { get; set; } public int Qty { get; set; } } class Program { static void Main(string[] args) { var numbers = new List<int>() { 10, 4, 8,10 }; var stock = new List<Stock>() { new Stock{Sku = "001", ModelName = "iphone11", Category = "iPhone 11", Qty = 5555 }, new Stock{Sku = "002", ModelName = "iphone11 pro", Category = "iPhone 11", Qty = 44 }, new Stock{Sku = "003", ModelName = "iphone11 pro max", Category = "iPhone 11", Qty = 100 }, new Stock{Sku = "004", ModelName = "iphone12", Category = "iPhone 12", Qty = 55 }, new Stock{Sku = "005", ModelName = "iphone12 pro", Category = "iPhone 12", Qty = 44 }, new Stock{Sku = "006", ModelName = "iphone12 pro max", Category = "iPhone 12", Qty = 10 }, }; var count = numbers.Count(); //ouput 4 var uniqueCount = numbers.Distinct().Count(); //ouput 3 var oddNumber = numbers.Count(s => s % 2 == 1);// ouput 0 var categoriesCount = (from c in stock group c by c.Category into d select (Category: d.Key, TotalStock: d.Count())); //output iPhone 11: 3; iPhone 12: 3 } }