Array Expressions in Power Automate Explained with Practical Examples

In Power Automate, array expressions are essential when working with multiple records, lists, or collections of data. Most real-world flows—especially those involving SharePoint, Dataverse, Outlook, or HTTP responses—depend heavily on arrays.

Understanding array expressions allows you to:

Process multiple items efficiently
Apply conditions on collections
Transform data for emails and reports
Build scalable and error-free flows

This article explains commonly used array expressions in Power Automate with clear explanations and step-by-step practical examples .

What Is an Array in Power Automate?

An array is a collection of values stored in a list format.

Simple Example

["HR", "IT", "Finance"]

Where Arrays Commonly Appear

Get items (SharePoint)
List rows (Dataverse)
Filter array
Split expression
HTTP responses

Practical Scenario Used in This Article

Business Requirement

We have a SharePoint list that stores employee requests.
We want to:

Read multiple records
Count them
Filter specific records
Combine values into a readable format

This will help demonstrate array expressions in real usage.

Step 1: SharePoint List Setup

Create a SharePoint list named Employee Requests .

Columns

Column Name	Type
Title	Single line of text
Department	Choice (HR, IT, Finance)
Status	Choice (New, Approved, Rejected)

Step 2: Create the Power Automate Flow

Go to Power Automate
Create an Instant cloud flow
Select Manually trigger a flow

This makes testing array expressions easier.

Step 3: Get Items (Array Source)

Add the Get items action.

Configuration

Site Address: Your site
List Name: Employee Requests

Important Output

  
    body('Get_items')?['value']

This output is an array of objects , where each object represents one list item.

Common Array Expressions with Examples

1. length() – Count Items in an Array

Purpose

Returns the number of elements in an array.

Expression

  
    length(body('Get_items')?['value'])

Use Case

Count number of requests
Validate if records exist

Output

2. empty() – Check if Array Is Empty

Purpose

Checks whether an array has no items.

Expression

  
    empty(body('Get_items')?['value'])

Use Case

Stop flow if no records are found
Avoid unnecessary loops

Output

3. first() – Get the First Item

Purpose

Returns the first element of an array.

Expression

  
    first(body('Get_items')?['value'])

Use Case

Fetch the earliest record
Preview sample data

Output

4. last() – Get the Last Item

Purpose

Returns the last element of an array.

Expression

  
    last(body('Get_items')?['value'])

Use Case

Get the most recent entry

Audit latest record

Output

5. join() – Convert Array to String

Purpose

Combines array values into a single string.

Practical Example

Step 1: Initialize Array Variable

Name: RequestTitles
Type: Array
Value: []

Step 2: Append Titles Inside Apply to each

  
    items('Apply_to_each')?['Title']

Step 3: Join Array

  
    join(variables('RequestTitles'), ', ')

Output

6. split() – Convert String to Array

Purpose

Splits a string into an array based on a delimiter.

Expression

  
    split('HR,IT,Finance', ',')

Use Case

Convert comma-separated values
Prepare data for looping

Output

Common Mistakes with Array Expressions

Treating arrays as single values
Forgetting Apply to each
Not handling empty arrays
Using conditions instead of Filter array
Formatting data before processing

Conclusion

Array expressions are a core part of Power Automate development.
Once you understand how to use functions like length(), join(), split(), and Filter array, handling complex data becomes simple and predictable.

Mastering array expressions significantly improves the reliability and scalability of your flows.