alt - script and chart function

The alt function returns the first of the parameters that has a valid number representation. If no such match is found, the last parameter will be returned. Any number of parameters can be used.

Syntax:  

alt(expr1[ , expr2 , expr3 , ...] , else)

Arguments:  

The alt function is often used with number or date interpretation functions. This way, Qlik Sense can test different date formats in a prioritized order. It can also be used to handle NULL values in numerical expressions.

Examples and results:

Example	Result
alt( date#( dat , 'YYYY/MM/DD' ), date#( dat , 'MM/DD/YYYY' ), date#( dat , 'MM/DD/YY' ), 'No valid date' )	This expression will test if the field date contains a date according to any of the three specified date formats. If so, it will return a dual value containing the original string and a valid number representation of a date. If no match is found, the text 'No valid date' will be returned (without any valid number representation).
alt(Sales,0) + alt(Margin,0)	This expression adds the fields Sales and Margin, replacing any missing value (NULL) with a 0.