How Do I: Extract value from string[]

Question

Hello:
 
I have a string[] and need to extract the fields. Can someone tell me how?
 
string[] Fields = { "File_ID, File_ID_Sub, Update_ID" };
 
fpor example what do I do if I need to get the 2nd field? How can I put it in a for loop to get all of them? How can I get the count of fields?