Power Automate (WDL) function
coalesce — Power Automate (WDL) function reference
First non-null value.
Syntax
wdl
coalesce(object1, object2, ...)
Examples
wdl
coalesce(item()?['Nick'], item()?['Name'], 'Guest')
→ First with a value
wdl
coalesce(item()?['MobilePhone'], item()?['BusinessPhone'], item()?['HomePhone'], 'No phone on file')
→ The first non-null phone field, or the fallback text
wdl
coalesce(triggerBody()?['UpdatedBy'], triggerBody()?['CreatedBy'])
→ Whichever field is populated
Also used under "Objects & JSON": first non-null of several fields.
wdl
coalesce(item()?['Mobile'], item()?['Phone'])
→ First with a value
Common mistakes & gotchas
- coalesce() only skips over null — an empty string '' or the number 0 counts as "a value," so a blank text field will not fall through to the next argument.
- It is variadic and evaluates left to right; if every argument is null it returns null rather than throwing.
Related Workflow Definition Language functions
From Logic & comparison