Question

If you have a List how do you return the item if a specified property or collection of properties exists?

public class Testing {     public string value1 { get; set; }     public string value2 { get; set; }     public int value3 { get; set; } } public class TestingList {     public void TestingNewList()     {         var testList = new List<Testing>                            {                                new Testing {value1 = 'Value1 - 1', value2 = 'Value2 - 1', value3 = 3},                                new Testing {value1 = 'Value1 - 2', value2 = 'Value2 - 2', value3 = 2},                                new Testing {value1 = 'Value1 - 3', value2 = 'Value2 - 3', value3 = 3},                                new Testing {value1 = 'Value1 - 4', value2 = 'Value2 - 4', value3 = 4},                                new Testing {value1 = 'Value1 - 5', value2 = 'Value2 - 5', value3 = 5},                                new Testing {value1 = 'Value1 - 6', value2 = 'Value2 - 6', value3 = 6},                                new Testing {value1 = 'Value1 - 7', value2 = 'Value2 - 7', value3 = 7}                            };          //use testList.Contains to see if value3 = 3         //use testList.Contains to see if value3 = 2 and value1 = 'Value1 - 2'       } } 

Answer 1

If you’re using .NET 3.5 or better, LINQ is the answer to this one:

testList.Where(t => t.value3 == 3); testList.Where(t => t.value3 == 2 && t.value1 == 'Value1 - 2'); 

If not using .NET 3.5 then you can just loop through and pick out the ones you want.