symbol-value (ANSI and GNU Common Lisp Document)

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#### 10.2.14 symbol-value [Accessor]

`symbol-value` symbol ⇒ value

(setf (`symbol-value` symbol) new-value)

#### Arguments and Values::

symbol—a symbol that must have a value.

value, new-value—an object.

#### Description::

Accesses the symbol’s value cell.

#### Examples::

     (setf (symbol-value 'a) 1) ⇒  1
     (symbol-value 'a) ⇒  1
     ;; SYMBOL-VALUE cannot see lexical variables.
     (let ((a 2)) (symbol-value 'a)) ⇒  1
     (let ((a 2)) (setq a 3) (symbol-value 'a)) ⇒  1
     ;; SYMBOL-VALUE can see dynamic variables.
     (let ((a 2))
       (declare (special a))
       (symbol-value 'a)) ⇒  2
     (let ((a 2))
       (declare (special a))
       (setq a 3)
       (symbol-value 'a)) ⇒  3
     (let ((a 2))
       (setf (symbol-value 'a) 3)
       a) ⇒  2
     a ⇒  3
     (symbol-value 'a) ⇒  3
     (let ((a 4))
       (declare (special a))
       (let ((b (symbol-value 'a)))
         (setf (symbol-value 'a) 5)
         (values a b))) ⇒  5, 4
     a ⇒  3
     (symbol-value :any-keyword) ⇒  :ANY-KEYWORD
     (symbol-value 'nil) ⇒  NIL
     (symbol-value '()) ⇒  NIL
     ;; The precision of this next one is implementation-dependent.
     (symbol-value 'pi) ⇒  3.141592653589793d0

#### Affected By::

makunbound, set, setq

#### Exceptional Situations::

Should signal an error of type type-error if symbol is not a symbol.

Should signal unbound-variable if symbol is unbound and an attempt is made to read its value. (No such error is signaled on an attempt to write its value.)

#### See Also::

boundp , makunbound , set , setq

#### Notes::

symbol-value can be used to get the value of a constant variable. symbol-value cannot access the value of a lexical variable.