The usual way to reference a variable is to write the symbol which names it. See Symbol Forms.
Occasionally, you may want to reference a variable which is only
determined at run time. In that case, you cannot specify the variable
name in the text of the program. You can use the symbol-value
function to extract the value.
This function returns the value stored in symbol’s value cell.
This is where the variable’s current (dynamic) value is stored. If
the variable has no local binding, this is simply its global value.
If the variable is void, a void-variable
error is signaled.
If the variable is lexically bound, the value reported by
symbol-value
is not necessarily the same as the variable’s
lexical value, which is determined by the lexical environment rather
than the symbol’s value cell. See Scoping Rules for Variable Bindings.
(setq abracadabra 5) ⇒ 5
(setq foo 9) ⇒ 9
;; Here the symbol abracadabra
;; is the symbol whose value is examined.
(let ((abracadabra 'foo))
(symbol-value 'abracadabra))
⇒ foo
;; Here, the value ofabracadabra
, ;; which isfoo
, ;; is the symbol whose value is examined. (let ((abracadabra 'foo)) (symbol-value abracadabra)) ⇒ 9
(symbol-value 'abracadabra) ⇒ 5