Question about LIST

Question

hi how are you please someone tell me why some of LISTs have useful methods like FIND , WHERE or ... and some of them dont have these methods

and how can i use these methods when those LISTs dont have

Answer 1

Your code is probably missing references to LINQ.

Add:

using System.Linq;

To your classes that don't have it, and add a reference to this assembly to projects that don't have it.

Answer 2

List has number of methods like Find, FindAll, FindIndex etc. To work with delegates, for example:

var op in _opList.Find(op => op != null)