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List <T> .Find (Predicates / Lambda)

Can someone tell me what is the difference / advantage between the following 3 Search Options:

        List<Employee> Employees = new List<Employee>();

        Employee tmp = new Employee();

        tmp.FirstName = "Randy";
        tmp.LastName = "Jones";
        Employees.Add(tmp);

        tmp.FirstName = "David";
        tmp.LastName = "Smith";
        Employees.Add(tmp);

        tmp.FirstName = "Michele";
        tmp.LastName = "Morris";
        Employees.Add(tmp);


        // Find option 1
        Employee eFound1= Employees.Find((Employee emp1) => {return emp1.LastName == "Jones";});

        // Find option 2
        Employee eFound2 = Employees.Find(emp2 => emp2.LastName == "Smith");

        // Find option 3
        Employee eFound3 = Employees.Find(
        delegate(Employee emp3)
        {
                return emp3.LastName == "Morris";
        }
        );

I read about lambdas and predicates (which I suspect is somehow related to the answer), but I can't put it all together. Any enlightenment will be appreciated!

Thanks david

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2 answers

The first is the lambda operator , the second is the lambda expression , and the third is the anonymous method .

All of them are functionally equivalent.

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. , int bool. , :

var numbers = Enumerable.Range(1,10);
var predicate = new Predicate<int>(pairNumber);
var pair_numbers = list.FindAll(predicate);

, :

bool pairNumber(int arg)
{
    return (arg % 2 == 0);
}

lambdas :

var numbers = Enumerable.Range(1,10);
var pair_values = list.FindAll(val => val % 2 == 0);

.

, , , . , :)

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