Question: There is a list of Employee (`List<Employee>`) and it contains objects of Employee and each Employee having Different property. One of the property is Employee Id. I want to add employee into list if that employee doesn't exists in the list and I want to check it through employee id using `List<T>.Exists(Predicate<T>)` method. How can I check the current employee id exists in the employee list or not. I got stuck here. Please help me out of this.

Answer: 
What about something like that `if (!yourList.Any(x => x.Id == Id))`

Do not forget about `using System.Linq;`

edit.

`if (!yourList.Exists(x => x.Id == Id)`
A predicate is a method that returns yes/no, true or false.
A predicate of T is a method that takes a an argument of T (and returns true or false).

`employees.Exists(e => e.Id == theId)`

would be passing an anonymous function as a predicate. You could also pass a normal method. If you have a method

bool EmployeeIdIsSeventeen(Employee e) {
 return e.Id == 17;
}

then you can call `employees.Exists(EmployeeIdIsSeventeen)` just as well.