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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, the DEFAULT_KEY value (third parameter) is applied.

Basic Usage

Array literal reference example:

derive value:ARRAYSTOMAP(["A","B"],["1","2","3"] ) as:'myMap'

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

Column reference example:

derive value:ARRAYSTOMAP(array1,array2, 'extraProps') as:'array2mapped'

Output: Generates a new array2mapped column containing 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:

derive value:ARRAYSTOMAP(array1,concat([array2,array3])) as:'array2map'

Output: Generates a new array2map column containing an Object pairing the elements of array1 and the array created by concatenating array2 and array3.

Syntax

derive value:ARRAYSTOMAP(array_keys,array_values, ['DEFAULT KEY'])

ArgumentRequired?Data TypeDescription
array_keysYstring or arrayName of column, array literal, or function returning an array whose elements are the keys for the generated Object
array_valuesYstring or arrayName of column, array literal, or function returning an array whose elements are the values for the generated Object
DEFAULT_KEYNstring literalAny 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 TypeExample Value
YesString (column reference, function returning an array) or array literalmyKeys

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 TypeExample Value
YesString (column reference, function returning an array) or array literalmyValues

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 TypeExample Value
NoString literal'extraProperties'

Examples

Example - Create an Object of product properties

Source:

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

ProdIdProdCategoryProdNameProdKeysProdProperties
S001ShirtsCrew Neck T-Shirt["type", "color", "fabric", "sizes"]["crew","blue","cotton","S,M,L","in stock","padded"]
S002ShirtsV-Neck T-Shirt["type", "color", "fabric", "sizes"]["v-neck","white","blend","S,M,L,XL","in stock","discount - seasonal"]
S003ShirtsTanktop["type", "color", "fabric", "sizes"]["tank","red","mesh","XS,S,M","discount - clearance","in stock"]
S004ShirtsTurtleneck["type", "color", "fabric", "sizes"]["turtle","black","cotton","M,L,XL","out of stock","padded"]

Transform:

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:

derive value: ARRAYSTOMAP(ProdProperties, ProdValues, 'ProdMiscProperties') as: 'prodPropertyMap'

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

drop col:ProdKeys

derive value:KEYS(prodPropertyMap) as:'ProdKeys'

 

Results:

ProdIdProdCategoryProdNameProdKeysProdPropertiesprodPropertyMap
S001ShirtsCrew 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" ] }
S002ShirtsV-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" ] }
S003ShirtsTanktop["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" ] }
S004ShirtsTurtleneck["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" ] }

 

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