iff()

Returns the value of then if if evaluates to true, or the value of else otherwise.

The iff() and iif() functions are equivalent

Syntax

iff(if, then, else)

Parameters

Name	Type	Required	Description
if	string	✓	An expression that evaluates to a boolean value.
then	scalar	✓	An expression that gets evaluated and its value returned from the function if if evaluates to `true`.
else	scalar	✓	An expression that gets evaluated and its value returned from the function if if evaluates to `false`.

Returns

This function returns the value of then if if evaluates to true, or the value of else otherwise.

Example

StormEvents
| extend Rain = iff((EventType in ("Heavy Rain", "Flash Flood", "Flood")), "Rain event", "Not rain event")
| project State, EventId, EventType, Rain

Output

The following table shows only the first 5 rows.

State	EventId	EventType	Rain
ATLANTIC SOUTH	61032	Waterspout	Not rain event
FLORIDA	60904	Heavy Rain	Rain event
FLORIDA	60913	Tornado	Not rain event
GEORGIA	64588	Thunderstorm Wind	Not rain event
MISSISSIPPI	68796	Thunderstorm Wind	Not rain event
...	...	...	...

countif() (aggregation function)isnotnull()