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 | |
|---|---|
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 | |
|---|---|
Parameter: Columns | ProdKeys |
Parameter: Action | Delete selected columns |
Transformation Name | |
|---|---|
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" ] } |