Variables (VAR/RETURN) in Power BI - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of using VAR in a DAX formula?

VAR lets you store a value or calculation temporarily inside a formula. It helps make formulas easier to read and faster to calculate by reusing the stored value.

beginner

How do you return the result of a variable in a DAX expression?

You use the RETURN keyword after defining variables with VAR. The expression after RETURN is the final output of the formula.

intermediate

Can you define multiple variables in a single DAX formula? How?

Yes, you can define multiple variables by writing several VAR statements one after another before the RETURN statement.

intermediate

Why is using variables in DAX formulas considered a best practice?

Variables improve readability, avoid repeating calculations, and can improve performance by calculating a value once and reusing it.

beginner

Write a simple DAX formula using VAR and RETURN to calculate the difference between total sales and total costs.

SalesMinusCosts = VAR TotalSales = SUM(Sales[Amount])<br>VAR TotalCosts = SUM(Costs[Amount])<br>RETURN TotalSales - TotalCosts

What keyword do you use to define a variable in a DAX formula?

A LET

B VAR

C DEFINE

D SET

VAR is the correct keyword to define variables in DAX.

What keyword follows variable definitions to specify the output in a DAX formula?

A RESULT

B OUTPUT

C END

D RETURN

RETURN specifies the final result after variables are defined.

Why might you use variables in a DAX formula?

A To store intermediate results for reuse

B To make formulas harder to read

C To avoid using RETURN

D To repeat calculations multiple times

Variables store intermediate results so you can reuse them, improving readability and performance.

Can you define more than one variable in a single DAX formula?

A No, only one variable per formula

B Yes, but only inside RETURN

C Yes, by writing multiple VAR statements before RETURN

D No, variables are not supported in DAX

You can define multiple variables by writing several VAR statements before the RETURN statement.

Which of these is a correct use of variables in DAX?

A VAR x = SUM(Sales[Amount]) RETURN x * 2

B LET x = SUM(Sales[Amount]) END x * 2

C DEFINE x = SUM(Sales[Amount]) RESULT x * 2

D SET x = SUM(Sales[Amount]) OUTPUT x * 2

Option A uses correct DAX syntax with VAR and RETURN.

Explain how to use VAR and RETURN in a DAX formula and why it is helpful.

Think about storing values and returning a final result.

Write a simple example of a DAX formula using two variables and returning their sum.

Use SUM or any simple calculation inside VAR.