Simple IEnumerator use with example

Question

I am having trouble remembering how  but not why  to use IEnumerators in C    I am used to Java with its wonderful documentation that explains everything to beginners quite nicely  So please  bear with me   I have tried learning from other answers on these boards to no avail  Rather than ask a generic question that has already been asked before  I have a specific example that would clarify things for me   Suppose I have a method that needs to be passed an IEnumerable lt String gt  object   All the method needs to do is concatenate the letters roxxors to the end of every String in the iterator  It then will return this new iterator  of course the original IEnumerable object is left as it was    How would I go about this   The answer here should help many with basic questions about these objects in addition to me  of course

User · Answer

I d do something like   private IEnumerable lt string gt  DoWork IEnumerable lt string gt  data        List lt string gt  newData   new List lt string gt         foreach string item in data                newData Add item    roxxors              return newData      Simple stuff

User · Answer

public IEnumerable lt string gt  Appender IEnumerable lt string gt  strings      List lt string gt  myList   new List lt string gt       foreach string str in strings            myList Add str    roxxors          return myList      or  public IEnumerable lt string gt  Appender IEnumerable lt string gt  strings      foreach string str in strings            yield return str    roxxors           using the yield construct  or simply  var newCollection   strings Select str   gt  str    roxxors            or   var newCollection   from str in strings select str    roxxors            where the two latter use LINQ and      is just syntactic sugar for

User · Answer

If i understand you correctly then in c  the yield return compiler magic is all you need i think   e g   IEnumerable lt string gt  myMethod IEnumerable lt string gt  sequence        foreach string item in sequence                 yield return item    roxxors

User · Answer

Also you can use LINQ s Select Method   var source   new      Line 1    Line 2      var result   source Select s   gt  s     roxxors      Read more here Enumerable Select Method

User · Answer

Here is the documentation on IEnumerator  They are used to get the values of lists  where the length is not necessarily known ahead of time  even though it could be   The word comes from enumerate  which means  to count off or name one by one    IEnumerator and IEnumerator lt T gt  is provided by all IEnumerable and IEnumerable lt T gt  interfaces  the latter providing both  in  NET via GetEnumerator    This is important because the foreach statement is designed to work directly with enumerators through those interface methods   So for example   IEnumerator enumerator   enumerable GetEnumerator     while  enumerator MoveNext          object item   enumerator Current         Perform logic on the item     Becomes   foreach object item in enumerable           Perform logic on the item     As to your specific scenario  almost all collections in  NET implement IEnumerable  Because of that  you can do the following   public IEnumerator Enumerate IEnumerable enumerable           List implements IEnumerable  but could be any collection      List lt string gt  list   new List lt string gt           foreach string value in enumerable                list Add value    roxxors              return list GetEnumerator

[c#] Simple IEnumerator use (with example)

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