• count item sequence &key from-end start end key test test-not → n
• count-if predicate sequence &key from-end start end key → n
• count-if-not predicate sequence &key from-end start end key → n

• item - an object.
• sequence - a proper sequence.
• predicate - a designator for a function of one argument that returns a generalized boolean.
• from-end - a generalized boolean. The default is false.
• test - a designator for a function of two arguments that returns a generalized boolean.
• test-not - a designator for a function of two arguments that returns a generalized boolean.
• start, end - bounding index designators of sequence. The defaults for start and end are 0 and nil, respectively.
• key - a designator for a function of one argument, or nil.
• n - a non-negative integer less than or equal to the length of sequence.

count, count-if, and count-if-not count and return the number of elements in the sequence bounded by start and end that satisfy the test.

The from-end has no direct effect on the result. However, if from-end is true, the elements of sequence will be supplied as arguments to the test, test-not, and key in reverse order, which may change the side-effects, if any, of those functions.

(count #\a "how many A's are there in here?") 

→

2 



(count-if-not #'oddp '((1) (2) (3) (4)) :key #'car) 

→

2 



(count-if #'upper-case-p "The Crying of Lot 49" :start 4) 

→

2 

None.

None.

Should be prepared to signal an error of type type-error if sequence is not a proper sequence.

• {\secref\TestFunctionRules}
• {\secref\TraversalRules}

The :test-not argument is deprecated.

The function count-if-not is deprecated.

\issue{TEST-NOT-IF-NOT:FLUSH-ALL} \issue{SUBSEQ-OUT-OF-BOUNDS} \issue{RANGE-OF-START-AND-END-PARAMETERS:INTEGER-AND-INTEGER-NIL} \issue{MAPPING-DESTRUCTIVE-INTERACTION:EXPLICITLY-VAGUE} \issue{TEST-NOT-IF-NOT:FLUSH-ALL}