Use of Expressions in Power Automate Flow
Microsoft Power Automate
If length of string is less than 250 , output string or slice the string to first 250
characters and return.
if(less(outputs('Compose_3'), 250), items('Apply_to_each_4')?['crbec_extraction_value'], slice(items('Apply_to_each_4')?['crbec_extraction_value'],0,250))
Use of expressions in power automate flows has been clearly explained the Microsoft's documentation.
Few sample expressions that are frequently used.
Check if string is empty. If empty pass 0 or length of string
if(empty(items('Apply_to_each_4')?['crbec_extraction_value']),0, length(items('Apply_to_each_4')?['crbec_extraction_value']))
https://learn.microsoft.com/en-us/power-automate/use-expressions-in-conditions