len
The number of items in an array or list, characters in text, or entries in a map.
xs(array) -- an array or list
Collections
append
Adds an item to the end. Given a name, the array itself grows (like xs.append(v)); a non-number item turns a number array into a list.
xs(array) -- an array or listitem(any) -- the item to add
concat
A new array or list: the first followed by the second.
xs(array) -- firstys(array) -- second
reverse
A new array or list in reverse order. (On a linked list, reverse animates the in-place reversal -- see Data Structures.)
xs(array) -- an array or list
sort
A new array sorted from smallest to largest, compared exactly (sqrt(2) sorts after 1.4142).
xs(array) -- an array of numbers
contains
Whether an array or list has an item equal to the value, text contains a piece of text, or a map has a key. (On a set, set membership -- see Sets.)
xs(array) -- an array or listitem(any) -- the value to look for
indexOf
The position (from 0) of the first item equal to the value, or -1 if there is none.
xs(array) -- an array or listitem(any) -- the value to look for
keys
A map's keys in the order they were added (a record's field names).
m(map) -- a map or record
values
A map's values in the order their keys were added.
m(map) -- a map or record
has
Whether a map has the key.
m(map) -- a map or recordkey(any) -- text, a number or true/false
delete
Removes a key (and its value) from a map, and shows the map.
m(map) -- a mapkey(any) -- the key to remove