hash-table-count (ANSI and GNU Common Lisp Document)

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#### 18.2.4 hash-table-count [Function]

`hash-table-count` hash-table ⇒ count

#### Arguments and Values::

hash-table—a hash table.

count—a non-negative integer.

#### Description::

Returns the number of entries in the hash-table. If hash-table has just been created or newly cleared (see clrhash) the entry count is `0`.

#### Examples::

     (setq table (make-hash-table)) ⇒  #<HASH-TABLE EQL 0/120 32115135>
     (hash-table-count table) ⇒  0
     (setf (gethash 57 table) "fifty-seven") ⇒  "fifty-seven"
     (hash-table-count table) ⇒  1
     (dotimes (i 100) (setf (gethash i table) i)) ⇒  NIL
     (hash-table-count table) ⇒  100

#### Affected By::

clrhash, remhash, setf of gethash

#### See Also::

hash-table-size

#### Notes::

The following relationships are functionally correct, although in practice using hash-table-count is probably much faster:

     (hash-table-count table) ≡
     (loop for value being the hash-values of table count t) ≡
     (let ((total 0))
       (maphash #'(lambda (key value)
                    (declare (ignore key value))
                    (incf total))
                table)
       total)