Array functions

CAQL provides functions for higher-level array manipulation. Also see the numeric functions for functions that work on number arrays.

Apart from that, CAQL also offers several language constructs:

simple array access of individual elements,
array comparison operators to compare each element in an array to a value or the elements of another array,

APPEND()

APPEND(anyArray, values, unique) → newArray

Add all elements of an array to another array. All values are added at the end of the array (right side).

It can also be used to append a single element to an array. It is not necessary to wrap it in an array (unless it is an array itself). You may also use PUSH() instead.

anyArray (array): array with elements of arbitrary type
values (array|any): array, whose elements shall be added to anyArray
unique (bool, optional): if set to true, only those values will be added that are not already contained in anyArray. The default is false.
returns newArray (array): the modified array

Examples

APPEND([ 1, 2, 3 ], [ 5, 6, 9 ])

// [ 1, 2, 3, 5, 6, 9 ]

APPEND([ 1, 2, 3 ], [ 3, 4, 5, 2, 9 ], true)

// [ 1, 2, 3, 4, 5, 9 ]

CONTAINS_ARRAY()

This is an alias for POSITION().

COUNT_DISTINCT()

COUNT_DISTINCT(anyArray) → number

Get the number of distinct elements in an array.

anyArray (array): array with elements of arbitrary type
returns number: the number of distinct elements in anyArray.

Examples

COUNT_DISTINCT([ 1, 2, 3 ])

// 3

COUNT_DISTINCT([ "yes", "no", "yes", "sauron", "no", "yes" ])

// 3

COUNT_UNIQUE()

This is an alias for COUNT_DISTINCT().

FIRST()

FIRST(anyArray) → firstElement

Get the first element of an array. It is the same as anyArray[0].

anyArray (array): array with elements of arbitrary type
returns firstElement (any|null): the first element of anyArray, or null if the array is empty.

Examples

FIRST([ 1, 2, 3 ])

// 1

FIRST([])

// null

INTERSECTION()

INTERSECTION(array1, array2, ... arrayN) → newArray

Return the intersection of all arrays specified. The result is an array of values that occur in all arguments.

Other set operations are UNION(), MINUS() and OUTERSECTION().

arrays (array, repeatable): an arbitrary number of arrays as multiple arguments (at least 2)
returns newArray (array): a single array with only the elements, which exist in all provided arrays. The element order is random. Duplicates are removed.

Examples

INTERSECTION( [1,2,3,4,5], [2,3,4,5,6], [3,4,5,6,7] )

// [ 5, 4, 3 ]

INTERSECTION( [2,4,6], [8,10,12], [14,16,18] )

// []

LAST()

LAST(anyArray) → lastElement

Get the last element of an array. It is the same as anyArray[-1].

anyArray (array): array with elements of arbitrary type
returns lastElement (any|null): the last element of anyArray or null if the array is empty.

Example

LAST( [1,2,3,4,5] )

// 5

LENGTH()

LENGTH(anyArray) → length

Determine the number of elements in an array.

anyArray (array): array with elements of arbitrary type
returns length (number): the number of array elements in anyArray.

LENGTH() can also determine the number of attribute keys of an object / document, and the character length of a string.

Input	Length
String	Number of Unicode characters
Number	Number of Unicode characters that represent the number
Array	Number of elements
Object	Number of first level elements
true	1
false	0
null	0

Examples

LENGTH( "🥑" )

// 1

LENGTH( 1234 )

// 4

LENGTH( [1,2,3,4,5,6,7] )

// 7

LENGTH( false )

// 0

LENGTH( {a:1, b:2, c:3, d:4, e:{f:5,g:6}} )

// 5

MINUS()

MINUS(array1, array2, ... arrayN) → newArray

Return the difference of all arrays specified.

Other set operations are UNION() and INTERSECTION().

arrays (array, repeatable): an arbitrary number of arrays as multiple arguments (at least 2)
returns newArray (array): an array of values that occur in the first array, but not in any of the subsequent arrays. The order of the result array is undefined and should not be relied on. Duplicates will be removed.

Example

MINUS( [1,2,3,4], [3,4,5,6], [5,6,7,8] )

// [ 2, 1 ]

NTH()

NTH(anyArray, position) → nthElement

Get the element of an array at a given position. It is the same as anyArray[position] for positive positions, but does not support negative positions.

anyArray (array): array with elements of arbitrary type
position (number): position of desired element in array, positions start at 0
returns nthElement (any|null): the array element at the given position. If position is negative or beyond the upper bound of the array, then null will be returned.

Examples

NTH( [ "foo", "bar", "baz" ], 2 )

// "baz"

NTH( [ "foo", "bar", "baz" ], 3 )

// null

NTH( [ "foo", "bar", "baz" ], -1 )

// null

POP()

POP(anyArray) → newArray

Remove the last element of array.

To append an element (right side), see PUSH().
To remove the first element, see SHIFT().
To remove an element at an arbitrary position, see REMOVE_NTH().

anyArray (array): an array with elements of arbitrary type
returns newArray (array): anyArray without the last element. If it's already empty or has only a single element left, an empty array is returned.

Examples

POP( [ 1, 2, 3, 4 ] )

// [ 1, 2, 3 ]

POP( [ 1 ] )

// []

POSITION()

POSITION(anyArray, search, returnIndex) → position

Return whether search is contained in array. Optionally return the position.

anyArray (array): the haystack, an array with elements of arbitrary type
search (any): the needle, an element of arbitrary type
returnIndex (bool, optional): if set to true, the position of the match is returned instead of a boolean. The default is false.
returns position (bool|number): true if search is contained in anyArray, false otherwise. If returnIndex is enabled, the position of the match is returned (positions start at 0), or -1 if it's not found.

Examples

POSITION( [2,4,6,8], 4 )

// true

POSITION( [2,4,6,8], 4, true )

// 1

PUSH()

PUSH(anyArray, value, unique) → newArray

Append value to anyArray (right side).

To remove the last element, see POP().
To prepend a value (left side), see UNSHIFT().
To append multiple elements, see APPEND().

anyArray (array): array with elements of arbitrary type
value (any): an element of arbitrary type
unique (bool): if set to true, then value is not added if already present in the array. The default is false.
returns newArray (array): anyArray with value added at the end (right side)

Note: The unique flag only controls if value is added if it's already present in anyArray. Duplicate elements that already exist in anyArray will not be removed. To make an array unique, use the UNIQUE() function.

Examples

PUSH([ 1, 2, 3 ], 4)

// [ 1, 2, 3, 4 ]

PUSH([ 1, 2, 2, 3 ], 2, true)

// [ 1, 2, 2, 3 ]

REMOVE_NTH()

REMOVE_NTH(anyArray, position) → newArray

Remove the element at position from the anyArray.

To remove the first element, see SHIFT().
To remove the last element, see POP().

anyArray (array): array with elements of arbitrary type
position (number): the position of the element to remove. Positions start at 0. Negative positions are supported, with -1 being the last array element. If position is out of bounds, the array is returned unmodified.
returns newArray (array): anyArray without the element at position

Examples

REMOVE_NTH( [ "a", "b", "c", "d", "e" ], 1 )

// [ "a", "c", "d", "e" ]

REMOVE_NTH( [ "a", "b", "c", "d", "e" ], -2 )

// [ "a", "b", "c", "e" ]

REPLACE_NTH()

Introduced in: v3.7.0

REPLACE_NTH(anyArray, position, replaceValue, defaultPaddingValue) → newArray

Replace the element at position in anyArray with replaceValue.

anyArray (array): array with elements of arbitrary type
position (number): the position of the element to replace. Positions start at 0. Negative positions are supported, with -1 being the last array element. If a negative position is out of bounds, then it is set to the first element (0)
replaceValue the value to be inserted at position
defaultPaddingValue to be used for padding if position is two or more elements beyond the last element in anyArray
returns newArray (array): anyArray with the element at position replaced by replaceValue, or appended to anyArray and possibly padded by defaultPaddingValue

It is allowed to specify a position beyond the upper array boundary:

replaceValue is appended if position is equal to the array length
if it is higher, defaultPaddingValue is appended to anyArray as many times as needed to place replaceValue at position
if no defaultPaddingValue is supplied in above case, then a query error is raised

Examples

REPLACE_NTH( [ "a", "b", "c" ], 1 , "z")

// [ "a", "z", "c" ]

REPLACE_NTH( [ "a", "b", "c" ], 3 , "z")

// [ "a", "b", "c", "z" ]

REPLACE_NTH( [ "a", "b", "c" ], 6, "z", "y" )
        
// [ "a", "b", "c", "y", "y", "y", "z" ]

REPLACE_NTH( [ "a", "b", "c" ], -1, "z" )

// [ "a", "b", "z" ]

REPLACE_NTH( [ "a", "b", "c" ], -9, "z" )

// [ "z", "b", "c" ]

REMOVE_VALUE()

REMOVE_VALUE(anyArray, value, limit) → newArray

Remove all occurrences of value in anyArray. Optionally with a limit to the number of removals.

anyArray (array): array with elements of arbitrary type
value (any): an element of arbitrary type
limit (number, optional): cap the number of removals to this value
returns newArray (array): anyArray with value removed

Examples

REMOVE_VALUE( [ "a", "b", "b", "a", "c" ], "a" )

// TODO

REMOVE_VALUE( [ "a", "b", "b", "a", "c" ], "a", 1 )

// TODO

REMOVE_VALUES()

REMOVE_VALUES(anyArray, values) → newArray

Remove all occurrences of any of the values from anyArray.

anyArray (array): array with elements of arbitrary type
values (array): an array with elements of arbitrary type, that shall be removed from anyArray
returns newArray (array): anyArray with all individual values removed

Example

REMOVE_VALUES( [ "a", "a", "b", "c", "d", "e", "f" ], [ "a", "f", "d" ] )

REVERSE()

REVERSE(anyArray) → reversedArray

Return an array with its elements reversed.

anyArray (array): array with elements of arbitrary type
returns reversedArray (array): a new array with all elements of anyArray in reversed order

Example

REVERSE ( [2,4,6,8,10] )

SHIFT()

SHIFT(anyArray) → newArray

Remove the first element of anyArray.

To prepend an element (left side), see UNSHIFT().
To remove the last element, see POP().
To remove an element at an arbitrary position, see REMOVE_NTH().

anyArray (array): array with elements with arbitrary type
returns newArray (array): anyArray without the left-most element. If anyArray is already empty or has only one element left, an empty array is returned.

Examples

SHIFT( [ 1, 2, 3, 4 ] )

SHIFT( [ 1 ] )

SLICE()

SLICE(anyArray, start, length) → newArray

Extract a slice of anyArray.

anyArray (array): array with elements of arbitrary type
start (number): start extraction at this element. Positions start at 0. Negative values indicate positions from the end of the array.
length (number, optional): extract up to length elements, or all elements from start up to length if negative (exclusive)
returns newArray (array): the specified slice of anyArray. If length is not specified, all array elements starting at start will be returned.

Examples

SLICE( [ 1, 2, 3, 4, 5 ], 0, 1 )

SLICE( [ 1, 2, 3, 4, 5 ], 1, 2 )

SLICE( [ 1, 2, 3, 4, 5 ], 3 )

SLICE( [ 1, 2, 3, 4, 5 ], 1, -1 )

SLICE( [ 1, 2, 3, 4, 5 ], 0, -2 )

SLICE( [ 1, 2, 3, 4, 5 ], -3, 2 )

SORTED()

SORTED(anyArray) → newArray

Sort all elements in anyArray. The function will use the default comparison order for CAQL value types.

anyArray (array): array with elements of arbitrary type
returns newArray (array): anyArray, with elements sorted

Example

SORTED( [ 8,4,2,10,6 ] )

SORTED_UNIQUE()

SORTED_UNIQUE(anyArray) → newArray

Sort all elements in anyArray. The function will use the default comparison order for CAQL value types. Additionally, the values in the result array will be made unique.

anyArray (array): array with elements of arbitrary type
returns newArray (array): anyArray, with elements sorted and duplicates removed

Example

SORTED_UNIQUE( [ 8,4,2,10,6,2,8,6,4 ] )

UNION()

UNION(array1, array2, ... arrayN) → newArray

Return the union of all arrays specified.

Other set operations are MINUS(), INTERSECTION() and OUTERSECTION().

arrays (array, repeatable): an arbitrary number of arrays as multiple arguments (at least 2)
returns newArray (array): all array elements combined in a single array, in any order

Examples

UNION(
    [ 1, 2, 3 ],
    [ 1, 2 ]
)

Note: No duplicates will be removed. In order to remove duplicates, please use either UNION_DISTINCT() or apply UNIQUE() on the result of UNION():

UNIQUE(
    UNION(
        [ 1, 2, 3 ],
        [ 1, 2 ]
    )
)

UNION_DISTINCT()

UNION_DISTINCT(array1, array2, ... arrayN) → newArray

Return the union of distinct values of all arrays specified.

arrays (array, repeatable): an arbitrary number of arrays as multiple arguments (at least 2)
returns newArray (array): the elements of all given arrays in a single array, without duplicates, in any order

Example

UNION_DISTINCT(
    [ 1, 2, 3 ],
    [ 1, 2 ]
)

UNIQUE()

UNIQUE(anyArray) → newArray

Return all unique elements in anyArray. To determine uniqueness, the function will use the comparison order.

anyArray (array): array with elements of arbitrary type
returns newArray (array): anyArray without duplicates, in any order

Example

UNIQUE( [ 1,2,2,3,3,3,4,4,4,4,5,5,5,5,5 ] )

UNSHIFT()

UNSHIFT(anyArray, value, unique) → newArray

Prepend value to anyArray (left side).

To remove the first element, see SHIFT().
To append a value (right side), see PUSH().

anyArray (array): array with elements of arbitrary type
value (any): an element of arbitrary type
unique (bool): if set to true, then value is not added if already present in the array. The default is false.
returns newArray (array): anyArray with value added at the start (left side)

Examples

UNSHIFT( [ 1, 2, 3 ], 4 )

UNSHIFT( [ 1, 2, 3 ], 2, true )

Array functions

APPEND()​

CONTAINS_ARRAY()​

COUNT_DISTINCT()​

COUNT_UNIQUE()​

FIRST()​

INTERSECTION()​

LAST()​

LENGTH()​

MINUS()​

NTH()​

POP()​

POSITION()​

PUSH()​

REMOVE_NTH()​

REPLACE_NTH()​

REMOVE_VALUE()​

REMOVE_VALUES()​

REVERSE()​

SHIFT()​

SLICE()​

SORTED()​

SORTED_UNIQUE()​

UNION()​

UNION_DISTINCT()​

UNIQUE()​

UNSHIFT()​

APPEND()

CONTAINS_ARRAY()

COUNT_DISTINCT()

COUNT_UNIQUE()

FIRST()

INTERSECTION()

LAST()

LENGTH()

MINUS()

NTH()

POP()

POSITION()

PUSH()

REMOVE_NTH()

REPLACE_NTH()

REMOVE_VALUE()

REMOVE_VALUES()

REVERSE()

SHIFT()

SLICE()

SORTED()

SORTED_UNIQUE()

UNION()

UNION_DISTINCT()

UNIQUE()

UNSHIFT()