In this section, we describe the functions that accept all types of arrays.
arrayp
object ¶This function returns t
if object is an array (i.e., a
vector, a string, a bool-vector or a char-table).
(arrayp [a])
⇒ t
(arrayp "asdf")
⇒ t
(arrayp (syntax-table)) ;; A char-table.
⇒ t
aref
arr index ¶This function returns the indexth element of the array or record arr. The first element is at index zero.
(setq primes [2 3 5 7 11 13]) ⇒ [2 3 5 7 11 13] (aref primes 4) ⇒ 11
(aref "abcdefg" 1)
⇒ 98 ; ‘b’ is ASCII code 98.
See also the function elt
, in Sequences.
aset
array index object ¶This function sets the indexth element of array to be object. It returns object.
(setq w (vector 'foo 'bar 'baz)) ⇒ [foo bar baz] (aset w 0 'fu) ⇒ fu w ⇒ [fu bar baz]
;; copy-sequence
copies the string to be modified later.
(setq x (copy-sequence "asdfasfd"))
⇒ "asdfasfd"
(aset x 3 ?Z)
⇒ 90
x
⇒ "asdZasfd"
The array should be mutable. See Mutability.
If array is a string and object is not a character, a
wrong-type-argument
error results. The function converts a
unibyte string to multibyte if necessary to insert a character.
fillarray
array object ¶This function fills the array array with object, so that each element of array is object. It returns array.
(setq a (copy-sequence [a b c d e f g])) ⇒ [a b c d e f g] (fillarray a 0) ⇒ [0 0 0 0 0 0 0] a ⇒ [0 0 0 0 0 0 0]
(setq s (copy-sequence "When in the course")) ⇒ "When in the course" (fillarray s ?-) ⇒ "------------------"
If array is a string and object is not a character, a
wrong-type-argument
error results.
The general sequence functions copy-sequence
and length
are often useful for objects known to be arrays. See Sequences.