C - using List T Find with custom objects

Question

I m trying to use a List lt T gt  with a custom class of mine  and being able to use methods like Contains    Find    etc   on the list  I thought I d just have to overload the operator    but apparently  one way of doing that is to use a delegate method with the Find       Note  Right now  I ve overloaded the Equals   method to get the Contains   method to work  but I still couldn t get the Find   function to work   What would be the best way of getting both to work   I m using the latest C    NET framework version with mono  on linux   edit  Here s my code  using System  namespace GuerreDesClans   public class Reponse   IEquatable lt Reponse gt        public Reponse                  m statement   string Empty          m pointage   0             public Reponse  string statement  int pointage                m pointage   pointage          m statement   statement                        attributs priv  s              private string m statement      private int m pointage                  properties              public string Statement           get   return m statement            set   m statement   value               public int Pointage           get   return m pointage            set   m pointage   value                         Equatable              public bool Equals  Reponse other                if  this m statement    other m statement              return true          else             return false               and how I would like to search my Reponse objects using the find   function     list find  statement1       would return a Reponse object

User · Answer

Previous answers don t account for the fact that you ve overloaded the equals operator and are using that to test for the sought element   In that case  your code would look like this   list Find x   gt  x    objectToFind     Or  if you don t like lambda syntax  and have overriden object Equals object  or have implemented IEquatable lt T gt   you could do this   list Find objectToFind Equals

User · Answer

Find   will find the element that matches the predicate that you pass as a parameter  so it is not related to Equals   or the    operator   var element   myList Find e   gt   some condition on e      In this case  I have used a lambda expression as a predicate  You might want to read on this  In the case of Find    your expression should take an element and return a bool   In your case  that would be   var reponse   list Find r   gt  r Statement     statement1     And to answer the question in the comments  this is the equivalent in  NET 2 0  before lambda expressions were introduced   var response   list Find delegate  Response r        return r Statement     statement1

User · Answer

http   msdn microsoft com en-us library x0b5b5bc aspx             Find a book by its ID          Book result   Books Find          delegate Book bk                        return bk ID    IDtoFind                               if  result    null                        DisplayResult result   Find by ID      IDtoFind                        else                       Console WriteLine   nNot found   0    IDtoFind

User · Answer

You can use find with a Predicate as follows   list Find x   gt  x Id    IdToFind     This will return the first object in the list which meets the conditions defined by the predicate  ie in my example I am looking for an object with an ID

User · Answer

It s easy  just use      list Find x   gt  x name     stringNameOfObjectToFind

[c#] C# - using List<T>.Find() with custom objects

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