Modify string

What it does

This action transforms, extracts, or stores data used by later workflow steps. The converted flow must preserve the source expression, output variable, and any formatting or type conversion behavior.

How Flow Migrator maps it

Flow Migrator maps this to Compose expression + Set variable using Data Operations / Variables. Maps common replace, substring, insert, remove, length, and index operations to Power Automate expressions and writes the result to the original output variable. Flow Migrator has a direct or proven best-effort conversion path for this mapping.

Common migration issues

• Validate expression syntax, data types, escaping, HTML output, and array/object handling in Power Automate.
• Run a test instance and compare outputs against the original Nintex workflow before production migration.

Validation checklist

1. Open the generated flow and confirm the action card imported correctly.
2. Validate connection references and required settings before running the flow.
3. Test with representative source data from the original workflow.