Yield C# Demo

YieldDemo.cs

// Source: https://www.c-sharpcorner.com/article/top-7-least-known-but-important-c-sharp-features/
// Check the two Filter() methods; note the difference - no temp collection needed
// YIELD PROVIDES STATEFUL ITERATION!

class Employee  
{  
     public string Name { get; set; }  
     public int Salary { get; set; }  
}  
  
class Program  
{
    static List<Employee> Employees = new List<Employee>()  
    {  
        new Employee{ Name="Tom", Salary=12000},  
        new Employee{ Name="Harry", Salary=15000},  
        new Employee{ Name="Sam", Salary=10000},  
        new Employee{ Name="Mike", Salary=25000},  
        new Employee{ Name="Bob", Salary=22000},  
        new Employee{ Name="Raj", Salary=18000},  
     };  
  
     static void Main(string[] args)  
     {  
             PrintData();  
     }  
  
     static void PrintData()  
     {  
         foreach (var emp in FilterWYield())  
         {  
             Console.WriteLine(emp.Name);  
         }  
  
         foreach (var emp in FilterSimple())  
         {  
             Console.WriteLine(emp.Name);  
         }  
     }  
  
  
     static IEnumerable<Employee> FilterWYield()  
     {  
         foreach (var item in Employees)  
         {  
             if (item.Salary >= 20000)  
                 yield return item;  
         }  
     }  
  
     static IEnumerable<Employee> FilterSimple()  
     {  
         List<Employee> emps = new List<Employee>();  
         foreach (var item in Employees)  
         {  
             if (item.Salary >= 20000)  
                 emps.Add(item);  
         }  
         return emps;  
     }  
 }