When does a variable gets calculated? Before or after RETURN?

Hi sahabatsuria 

In DAX (Data Analysis Expressions) for Power BI, variables are calculated before the RETURN statement. When you define a variable using the VAR keyword, its value is computed immediately, and this value is then used in the expression that follows the RETURN statement 

Here’s a simple example to illustrate:

Customer% =
VAR SalesAmount = SUMX(Sales, Sales[Quantity] * Sales[Net Price])
VAR NumCustomers = DISTINCTCOUNT(Sales[CustomerKey])
RETURN DIVIDE(SalesAmount, NumCustomers)

In this example:

• SalesAmount and NumCustomers are calculated first.
• The RETURN statement then uses these pre-calculated values to compute the final result.

This approach helps improve readability and performance of your DAX code

Still If you need more information, pls go through follwing documentation

https://learn.microsoft.com/en-us/dax/best-practices/dax-variables

https://dax.guide/st/var/

https://www.sqlbi.com/articles/when-are-variables-evaluated-in-dax/

Thanks!