SP Online Flow add() syntax

Question

New to using flows in SP Online so I'm simply trying to add two numbers in one list(parent), using flow, and place that value into another list(child).

Fields are val1 and val2 and they are numeric fields in the parent. The destination field in the child is result and is also a numeric field.

The syntax in the Compose statement is (including quotes):

"@add(item()?['val1'],item()?['val2'])" 

But the update fails. Flow is set to run on newly created items. val1/val2=3.

I copied this syntax from a YouTube video and then tried various combinations to get it to work. They either failed on the save or failed when ran.

The error I'm getting is:

Unable to process template language expressions in action 'Compose' inputs at line '1' and column '2633': 'The template language function 'add' expects its first parameter to be an integer or a decimal number. The provided value is of type 'Null'. Please see https://aka.ms/logicexpressions#add for usage details.'.

Help with this syntax would be greatly appreciated.

Answer 1

The syntax for add function is like below:

add(<summand_1>, <summand_2>)

Where, <summand_1>, <summand_2> should of type Integer, Float, or mixed.

Reference: Flow - add() function.

Solution:

For your case you can use Compose action to enter the Dynamic content of the corresponding SharePoint field and then use add() function to get the sum of these two fields as given below:

Expression:

add(outputs('Compose-ColumnA'),outputs('Compose-ColumnB'))

Reference: Add function with dynamic content.