Use yield break : Yield : Data Structure C# Examples

    
using  System;  
using  System.Collections;  
  
class  MyClass  {  
    char  ch  =  'A';  
  
    public  IEnumerator  GetEnumerator()  {  
        for(int  i=0;  i  <  26;  i++)  {  
            if(i  ==  10)  
                  yield  break;  //  stop  iterator  early  
            yield  return  (char)  (ch  +  i);  
        }  
    }  
}  
  
class  MainClass  {  
    public  static  void  Main()  {  
        MyClass  mc  =  new  MyClass();  
  
        foreach(char  ch  in  mc)  
            Console.Write(ch  +  "  ");  
  
        Console.WriteLine();  
    }  
}