| item | an item to be found |
| sequence | a sequence to be searched |
| test | function key and item comparison |
| from-end | direction of search, default is NIL - forward |
| start | starting position for search, default is 0 |
| end | final position for search, default is NIL - end of sequence |
| key | function for extracting value before test |
| test | function for comparison of two values |
| test-not | function for comparison of two values |
COUNT function counts specified elements in sequence. Return value is number of occurancesf or NIL if no occurance is not found. See also COUNT-IF, POSITION, POSITION-IF, FIND, FIND-IF and MEMBER.
(count #\s "Some sequence") => 1 (count #\s "Some sequence" :key #'char-downcase) => 2 (count #\s "Some sequence" :key #'char-downcase :start 1) => 1 (count #\x "Some sequence") => 0 (count '(1 2) #(9 3 (1 2) 6 7 8)) => 0 (count '(1 2) #(9 3 (1 2) 6 7 8) :test #'equal) => 1 (count 1 #(0 1 0 0 0 1 0) :from-end t) => 2