null-safe access ?[ ] — Power Automate (WDL) function reference

Read a field without failing.

Syntax

wdl

expression?['propertyName']

wdl

body('Get_item')?['Author']?['Email']

→ A value or null

wdl

triggerBody()?['Customer']?['Address']?['City']

→ A value or null, safely chained through three levels

wdl

if(equals(item()?['Approver']?['Email'], null), 'unassigned', item()?['Approver']?['Email'])

→ The approver email, or "unassigned"

Chain ?[ ] through every level. One missing link otherwise breaks the whole expression.
?[ ] only guards the immediate property lookup — if item()?['Customer'] itself is null and the next access doesn't also use ?[ ], that next access still throws.
Without the leading ?, a plain ['propertyName'] access throws immediately when the property doesn't exist, rather than returning null — always use ?[ ] on anything sourced from a trigger or connector whose schema isn't guaranteed.

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