r.Id == 63);
//returns default value if element not found. For refenrence types this is null!
var firstCustomer = customers.FirstOrDefault(customer =&gt; customer.Id == 63);
var lastCustomer = customers.LastOrDefault(customer =&gt; customer.Id == 63);
//You can specify the default return value with the 2nd parameter:
var firstCustomer = customers.FirstOrDefault(customer =&gt; customer.Id == 63, new Cutomer());
var lastCustomer = customers.LastOrDefault(customer =&gt; customer.Id == 63, new Customer());
</co