Power Fx function
Complete A–Z reference
Validate
Checks a value against data source rules.
What it does
Checks a value against data source rules.
The job: Every function, signal, and operator entry in the canvas-apps reference.
How to use Validate
Start from the task, not the alphabet. If you are shaping rows for a gallery, reach for Validate alongside the other data functions in its group; if you are saving, navigating, or changing state, use it on an event such as a button OnSelect rather than in a display property. When a formula misbehaves, check for a blank value where you expected text, then confirm the behaviour against the examples in the Power Fx function reference hub.
New to the language itself? Read What Is Microsoft Power Fx? first, then come back here when you need this specific tool.