>>>I have updated my answer
>>
>>I have a compiler warning (green underline) under this test
>>
>>

>> public static Int32 Occurs(this String source, char pattern)
>>      {
>>         if (null==pattern)
>>            return 0;
>>         return source.Split(pattern).Length - 1;
>>      }

>>
>>It is saying that value of type int never equals null.
>>
>>So, do I really need this test here for char?
>
>
>No - I only mentioned for pattern = string

I guess I misunderstood you. I removed that test from the first method and onle kept in the second with String.IsNullOrEmpty check.

Thanks again.