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ARRAYSTOMAP Function

Combines one array containing keys and another array containing values into an Object of key-value pairs.

  • This function applies to two inputs only.

  • Inputs can be array literals, column references, or functions returning arrays.

If the number of key elements is greater than the number of value elements, null values are generated for the missing values in the output Object. If the number of value elements is greater, theDEFAULT_KEYvalue (third parameter) is applied.

Wrangle vs. SQL: This function is part of Wrangle, a proprietary data transformation language. Wrangle is not SQL. For more information, see Wrangle Language.

Basic Usage

Array literal reference example:

arraystomap(["A","B"],["1","2","3"])

Output:Returns an Object associating keys from the first array with values from the second array.

Column reference example:

arraystomap(array1,array2, 'extraProps')

Output: Returns an Object pairing the elements of the arrays as key-value pairs. Any extra values in array2 are assigned to the extraProps key.

Function reference example:

arraystomap(array1,concat([array2,array3]))

Output: Returns an Object pairing the elements of array1 and the array created by concatenating array2 and array3.

Syntax and Arguments

arraystomap(array_keys,array_values, ['DEFAULT KEY'])

Argument

Required?

Data Type

Description

array_keys

Y

string or array

Name of column, array literal, or function returning an array whose elements are the keys for the generated Object

array_values

Y

string or array

Name of column, array literal, or function returning an array whose elements are the values for the generated Object

DEFAULT_KEY

N

string literal

Any extra values are assigned to this specified key

For more information on syntax standards, see Language Documentation Syntax Notes.

array_keys

Name of the array column, array literal, or function returning an array whose elements you want to use as the keys for the Object.

Usage Notes:

Required?

Data Type

Example Value

Yes

String (column reference, function returning an array) or array literal

myKeys

array_values

Name of the array column, array literal, or function returning an array whose elements you want to use as the values in the Object.

Usage Notes:

Required?

Data Type

Example Value

Yes

String (column reference, function returning an array) or array literal

myValues

DEFAULT KEY

If there are extra elements in the second array, they are assigned to the key that is defined by this parameter.

Usage Notes:

Required?

Data Type

Example Value

No

String literal

'extraProperties'

Examples

Astuce

For additional examples, see Common Tasks.

Example - Create an Object of product properties

This example illustrates how to use the ARRAYSTOMAP and KEYS functions to convert values in Array or Object data type of key-value pairs.

Functions:

Item

Description

ARRAYSTOMAP Function

Combines one array containing keys and another array containing values into an Object of key-value pairs.

KEYS Function

Extracts the key values from an Object data type column and stores them in an array of String values.

Source:

Your dataset contains master product data with product properties stored in two arrays of keys and values.

ProdId

ProdCategory

ProdName

ProdKeys

ProdProperties

S001

Shirts

Crew Neck T-Shirt

["type", "color", "fabric", "sizes"]

["crew","blue","cotton","S,M,L","in stock","padded"]

S002

Shirts

V-Neck T-Shirt

["type", "color", "fabric", "sizes"]

["v-neck","white","blend","S,M,L,XL","in stock","discount - seasonal"]

S003

Shirts

Tanktop

["type", "color", "fabric", "sizes"]

["tank","red","mesh","XS,S,M","discount - clearance","in stock"]

S004

Shirts

Turtleneck

["type", "color", "fabric", "sizes"]

["turtle","black","cotton","M,L,XL","out of stock","padded"]

Transformation:

When the above data is loaded into the Transformer page, you might need to clean up the two array columns.

Using the following transform, you can map the first element of the first array as a key for the first element of the second, which is its value. You might notice that the number of keys and the number of values are not consistent. For the extra elements in the second array, the default key of ProdMiscProperties is used:

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

ARRAYSTOMAP(ProdProperties, ProdValues, 'ProdMiscProperties')

Parameter: New column name

'prodPropertyMap'

You can now use the following steps to generate a new version of the keys:

Transformation Name

Delete columns

Parameter: Columns

ProdKeys

Parameter: Action

Delete selected columns

Transformation Name

New formula

Parameter: Formula type

Single row formula

Parameter: Formula

KEYS(prodPropertyMap)

Parameter: New column name

'ProdKeys'

Results:

ProdId

ProdCategory

ProdName

ProdKeys

ProdProperties

prodPropertyMap

S001

Shirts

Crew Neck T-Shirt

["type", "color", "fabric", "sizes","ProdMiscProperties"]

["crew","blue","cotton","S,M,L","in stock","padded"]

{
  "type": [ "crew" ],
  "color": [ "blue" ],
  "fabric": [ "cotton" ],
  "sizes": [ "S,M,L" ],
  "ProdMiscProperties": [ "in stock", "padded" ] }

S002

Shirts

V-Neck T-Shirt

["type", "color", "fabric", "sizes","ProdMiscProperties"]

["v-neck","white","blend","S,M,L,XL","in stock","discount - seasonal"]

{
  "type": [ "v-neck" ],
  "color": [ "white" ],
  "fabric": [ "blend" ],
  "sizes": [ "S,M,L,XL" ],
  "ProdMiscProperties": [ "in stock", "discount - seasonal" ] }

S003

Shirts

Tanktop

["type", "color", "fabric", "sizes","ProdMiscProperties"]

["tank","red","mesh","XS,S,M","discount - clearance","in stock"]

{
  "type": [ "tank" ],
  "color": [ "red" ],
  "fabric": [ "mesh" ],
  "sizes": [ "XS,S,M" ],
  "ProdMiscProperties": [ "discount - clearance", "in stock" ] }

S004

Shirts

Turtleneck

["type", "color", "fabric", "sizes","ProdMiscProperties"]

["turtle","black","cotton","M,L,XL","out of stock","padded"]

{
  "type": [ "turtle" ],
  "color": [ "black" ],
  "fabric": [ "cotton" ],
  "sizes": [ "M,L,XL" ],
  "ProdMiscProperties": [ "out of stock", "padded" ] }