flatten.md

flatten

Flattens a nested array or extracts property values from an array of objects.

Syntax

flatten(array)
flatten(arrayOfObjects.property)

Parameters

Parameter	Type	Description
array	Array	The array to flatten or property path to extract

Returns

Array - A flattened array of values.

Description

The flatten function can flatten nested arrays into a single-level array, or extract all values of a specific property from an array of objects. This is essential for preparing data for aggregate functions.

Examples

Flatten Nested Arrays

Result = FLATTEN([[1, 2], [3, 4], [5]])
// Result: [1, 2, 3, 4, 5]

Extract Property Values

// Given AppData.Cities with objects containing 'population' property
Populations = FLATTEN(AppData.Cities.population)
// Result: [39538223, 29145505, 21538187, ...]

With Aggregate Functions

// Sum all populations
TotalPopulation = SUM(FLATTEN(AppData.Cities.population))

Chain Operations

// Get average of extracted values
AverageScore = AVG(FLATTEN(AppData.Students.score))

Use Cases

• Data extraction: Get property values from object arrays
• Array processing: Flatten nested structures
• Aggregation prep: Prepare data for SUM, AVG, etc.
• Data transformation: Restructure array data

Related Functions

• sum - Sum flattened values
• avg - Average flattened values
• objectkeystoarray - Extract object keys
• objectvaluestoarray - Extract object values

Notes

• Critical for preparing data for aggregate functions
• Works with both nested arrays and object arrays
• Uses the Math service's flatten method
• Commonly used in data pipelines