lispdoc - results for gethash

(gethash key hash-table &optional default)
Function: Finds the entry in HASH-TABLE whose key is KEY and returns the associated value and T as multiple values, or returns DEFAULT and NIL if there is no such entry. Entries can be added using SETF.
Example:
(defun rl-get-rule-def (name)
  (gethash name *rule-defs*))
Mentioned in:
CLtL2 - 16. Hash Tables
CLtL2 - 16.1. Hash Table Functions
CLtL2 - A.2.1. Scanners
HyperSpec - Accessor GETHASH
On Lisp - Anaphoric Variants
On Lisp - Common Lisp Evolves
On Lisp - Compiling Networks
On Lisp - Functions as Representation
On Lisp - Objects in Plain Lisp
PCL - generalized assignment
PCL - hash table iteration
PCL - hash tables
PCL - multiple values
Successful Lisp - hash tables
(alexandria.0.dev:ensure-gethash key hash-table &optional default)
Function: Like GETHASH, but if KEY is not found in the HASH-TABLE saves the DEFAULT under key before returning it. Secondary return value is true if key was already in the table.