Regular Expression  Example                Notes  
 /Sheep/           "Sheep"                      
 /[Ss]heep/        "a sheep named Sheep"     
 [A-Z]             an uppercase leetter      
 /[123456789]/     any digit                 
 /[^Ss]/           neither "S" nor "s"       carat is first char after "["
 /[^A-Z]/          not an upper-case letter  carat is first char after "["
 /[^\.]            not a period              carat is first char after "["
 /[a^]/            "a" or "^"
 /A^b/             the pattern "A^b" 
 /dogs?/           "dog" or "dogs"
 dogs*             "dog" or "dogsssss"       zero or more of the preceding char Kleene *, pronounced "cleany star"