Array function parameters - CDN - Alibaba Cloud Documentation Center

This topic describes the syntax, parameters, return values, and examples of array functions.

arr_concat

Concatenates elements of an array into a single string, with an optional separator.

Syntax: arr_concat(tbl, sep) → String

Parameter	Required	Default	Description
`tbl`	Yes	—	The array whose elements you want to concatenate.
`sep`	No	`""` (empty string)	The separator inserted between elements.

Example

d = ['t1','t2','t3']
say(arr_concat(d, '&'))
-- Output: t1&t2&t3

arr_insert

Inserts an element into an array at a specified position.

Syntax: arr_insert(list, value, [pos]) → Boolean

Parameter	Required	Default	Description
`list`	Yes	—	The array to insert into.
`value`	Yes	—	The element to insert. Accepts any data type.
`pos`	No	End of array	The 1-based index at which to insert the element. Must be a non-zero integer. Elements after the insertion point shift toward the end.

Returns true.

Example

tbl_1 = []
arr_insert(tbl_1, '1')
arr_insert(tbl_1, '3')
arr_insert(tbl_1, '5')
arr_insert(tbl_1, '2')
arr_insert(tbl_1, '6', 1)
str = arr_concat(tbl_1, '')
say(concat('arr_insert:', str))
-- Output: arr_insert:61352

arr_remove

Removes an element from an array at a specified position and returns it.

Syntax: arr_remove(list, [pos]) → Any

Parameter	Required	Default	Description
`list`	Yes	—	The array to remove from.
`pos`	No	Last element	The index of the element to remove.

Returns the removed element.

Example

tbl_1 = []
arr_insert(tbl_1, '1')
arr_insert(tbl_1, '3')
arr_insert(tbl_1, '5')
arr_insert(tbl_1, '2')
say(concat('arr_remove:', arr_remove(tbl_1, 2)))
-- Output: arr_remove:3

arr_sort

Sorts the elements of an array in place.

Syntax: arr_sort(list, [comp]) → Boolean

Parameter	Required	Default	Description
`list`	Yes	—	The array to sort.
`comp`	No	ANSII ascending	A comparator function that determines element order.

Comparator behavior

`comp(a, b)` return value	Sort order
`comp` not provided	Elements are sorted by ANSII code in ascending order. Elements with equal ANSII values may be reordered.
`true`	`a` is placed before `b`.
`false`	`b` is placed before `a`.

Note: The comp function receives two elements from list as arguments. To sort in descending order, return true when a > b.

Returns true.

Example

tbl_1 = []
arr_insert(tbl_1, '1')
arr_insert(tbl_1, '3')
arr_insert(tbl_1, '5')
arr_insert(tbl_1, '2')
say(concat('remove:', arr_remove(tbl_1, 2)))
str = arr_concat(tbl_1, '')
say(concat('insert:', str))
arr_sort(tbl_1)
str = arr_concat(tbl_1, '')
say(concat('sort:', str))
def my_comp(a, b){
  a = tonumber(a)
  b = tonumber(b)
  if gt(a, b) {
    return true
  }
  return false
}
arr_sort(tbl_1, my_comp)
str = arr_concat(tbl_1, '')
say(concat('sort_comp:', str))
-- Output:
-- remove:3
-- insert:152
-- sort:125
-- sort_comp:521

arr_len

Returns the number of elements in an array.

Syntax: arr_len(arr) → Number

Parameter	Required	Description
`arr`	Yes	The array to count.

Example

d = []
set(d, 1, 'v1')
say(arr_len(d))
-- Output: 1