How to Convert Array to String in Power Automate

When working with Power Automate, you may encounter situations where data is stored in an array format, but a string output is required for emails, notifications, reports, or file generation.

Power Automate provides the join() expression, which allows you to combine multiple array elements into a single string using a specified delimiter.

Why Convert Arrays to Strings?

Create readable email content
Generate reports
Store values in text fields
Format notifications
Prepare data for external systems

Using the join() Function

The join() function combines all values in an array into a single string.

join(
createArray('Apple','Orange','Banana'),
', '
)

Output:

Apple, Orange, Banana

Using Dynamic Array Values

You can convert arrays retrieved from SharePoint, Dataverse, Excel, or APIs into strings.

join(
variables('SelectedItems'),
', '
)

Using Different Delimiters

The delimiter can be customized based on requirements.

join(
variables('Departments'),
' | '
)

Example Output:

Sales | Marketing | Finance

Creating Email Content

Arrays are frequently converted into strings before sending email notifications.

concat(
'Selected Products: ',
join(
variables('Products'),
', '
)
)

Example Output:

Selected Products: Laptop, Mouse, Keyboard Important: The join() function works only with arrays. Ensure the input value is an array before applying the expression.

Common Use Cases

Email notifications
Approval workflows
Report generation
Dataverse text fields
SharePoint updates
API integrations

Best Practices

Validate array contents before conversion.
Choose meaningful delimiters.
Handle empty arrays gracefully.
Use join() instead of loops when possible.
Test output formatting thoroughly.

Key Takeaways

join() is the primary function for converting arrays to strings.
Custom delimiters can be used to format output.
Works with dynamic arrays from multiple data sources.
Useful for emails, reports, and integrations.
Simplifies data transformation in Power Automate.