Logical functions (IF, IIF, CASE) in Tableau - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the IF function do in Tableau?

The IF function checks a condition and returns one value if the condition is true, and another value if it is false.

beginner

How is IIF different from IF in Tableau?

IIF is a shorthand for IF that always requires three parts: condition, value if true, and value if false. It is simpler for quick true/false checks.

intermediate

What is the purpose of the CASE function in Tableau?

CASE evaluates an expression and compares it to multiple values, returning the matching result. It is like a cleaner way to write multiple IF statements.

beginner

Write a simple IF statement in Tableau to check if Sales are greater than 1000.

IF [Sales] > 1000 THEN 'High' ELSE 'Low' END

intermediate

When should you use CASE instead of multiple IF statements?

Use CASE when you have one expression to compare against many fixed values. It makes your formula easier to read and maintain.

Which function in Tableau requires a condition, a true result, and a false result all in one line?

A IIF

B IF

C CASE

D SUM

IIF requires condition, true result, and false result in one line, making it a shorthand for IF.

What does the CASE function do?

A Checks one expression against multiple values

B Calculates sum of values

C Filters data

D Creates a new data source

CASE compares one expression to multiple values and returns the matching result.

Which keyword ends an IF statement in Tableau?

A DONE

B STOP

C FINISH

D END

IF statements in Tableau must end with the keyword END.

What will this formula return if [Sales] = 500?
IF [Sales] > 1000 THEN 'High' ELSE 'Low' END

A 'High'

B 'Low'

C Error

D Null

Since 500 is not greater than 1000, the ELSE part returns 'Low'.

Which function is best for checking multiple conditions with different outcomes?

A AVG

B SUM

C CASE

D IIF

CASE is best for multiple conditions with different outcomes based on one expression.

Explain how IF and IIF functions work in Tableau and when you might use each.

Think about how you check conditions and return values.

Describe a scenario where using CASE is better than multiple IF statements in Tableau.

Consider when you compare one value to many options.

Practice

1. Which logical function in Tableau is best for checking a simple true or false condition?

easy

A. IF

B. CASE

C. IIF

D. SWITCH

Solution

1. Step 1: Understand the purpose of IF

   The IF function evaluates a condition and returns one value if true and another if false, perfect for simple true/false checks.

2. Step 2: Compare with other functions

   CASE is for multiple fixed values, IIF is a shorthand for IF but with null handling, and SWITCH is not a Tableau function.

3. Final Answer:

   IF -> Option A

4. Quick Check:

   Simple true/false check = IF [OK]

Hint: Use IF for simple true/false decisions [OK]

Common Mistakes:

• Confusing CASE with IF for simple conditions
• Using IIF without needing null handling
• Thinking SWITCH is a Tableau function

2. Which of the following is the correct syntax for the IIF function in Tableau?

easy

A. IIF(condition ? true_result : false_result)

B. IIF(condition THEN true_result ELSE false_result END)

C. IIF(condition, true_result, false_result)

D. IIF(condition, true_result)

Solution

1. Step 1: Recall IIF syntax

   IIF takes three arguments: a condition, the result if true, and the result if false, written as IIF(condition, true_result, false_result).

2. Step 2: Check other options

   IIF(condition THEN true_result ELSE false_result END) uses IF syntax, C uses ternary operator syntax (not Tableau), and D misses the false_result argument.

3. Final Answer:

   IIF(condition, true_result, false_result) -> Option C

4. Quick Check:

   IIF syntax = IIF(condition, true, false) [OK]

Hint: IIF always needs three parts: condition, true, false [OK]

Common Mistakes:

• Omitting the false_result argument
• Using IF syntax inside IIF
• Confusing with ternary operator syntax

3. What will be the result of this Tableau calculation?

CASE [Region]
  WHEN 'East' THEN 'Group A'
  WHEN 'West' THEN 'Group B'
  ELSE 'Other'
END

If [Region] is 'West'?

medium

A. 'Group A'

B. 'Group B'

C. 'Other'

D. Null

Solution

1. Step 1: Understand CASE evaluation

   The CASE statement checks [Region] value. If it matches 'West', it returns 'Group B'.

2. Step 2: Apply the input value

   Since [Region] is 'West', the second WHEN condition matches, so output is 'Group B'.

3. Final Answer:

   'Group B' -> Option B

4. Quick Check:

   CASE 'West' = 'Group B' [OK]

Hint: CASE returns first matching WHEN value [OK]

Common Mistakes:

• Choosing ELSE value when a WHEN matches
• Confusing CASE with IF syntax
• Assuming Null if no match without ELSE

4. Identify the error in this Tableau formula:

IF [Sales] > 1000 THEN 'High' ELSEIF [Sales] > 500 THEN 'Medium' ELSE 'Low' END

medium

A. ELSEIF should be ELSE IF (two words)

B. Missing END keyword

C. Incorrect use of ELSE instead of ELSEIF

D. IF cannot compare numeric values

Solution

1. Step 1: Check IF syntax in Tableau

   Tableau requires ELSE IF as two separate words, not ELSEIF as one word.

2. Step 2: Verify other parts

   The formula has END keyword, ELSE is used correctly, and IF can compare numbers.

3. Final Answer:

   ELSEIF should be ELSE IF (two words) -> Option A

4. Quick Check:

   Use ELSE IF, not ELSEIF in Tableau [OK]

Hint: Use ELSE IF as two words in Tableau IF statements [OK]

Common Mistakes:

• Writing ELSEIF as one word
• Forgetting END keyword
• Thinking IF can't compare numbers

5. You want to create a calculated field that labels sales as 'Low' if below 500, 'Medium' if between 500 and 1000, and 'High' if above 1000. Which Tableau formula correctly uses logical functions to do this?

hard

A. IF [Sales] <= 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSE 'High' END

B. CASE WHEN [Sales] < 500 THEN 'Low' WHEN [Sales] <= 1000 THEN 'Medium' ELSE 'High' END

C. IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSE 'High' END

D. IIF([Sales] < 500, 'Low', IIF([Sales] <= 1000, 'Medium', 'High'))

Solution

1. Step 1: Analyze the requirement

   We need three labels based on sales ranges: below 500, 500 to 1000, and above 1000.

2. Step 2: Evaluate each option

   IF [Sales] < 500 THEN 'Low' ELSEIF [Sales] <= 1000 THEN 'Medium' ELSE 'High' END uses ELSEIF (incorrect syntax, should be ELSE IF). CASE WHEN [Sales] < 500 THEN 'Low' WHEN [Sales] <= 1000 THEN 'Medium' ELSE 'High' END uses CASE incorrectly because CASE in Tableau matches exact values, not ranges. IF [Sales] <= 500 THEN 'Low' ELSEIF [Sales] < 1000 THEN 'Medium' ELSE 'High' END has overlapping conditions and incorrect ELSE IF syntax. IIF([Sales] < 500, 'Low', IIF([Sales] <= 1000, 'Medium', 'High')) correctly nests IIF functions to handle ranges properly.

3. Final Answer:

   IIF([Sales] < 500, 'Low', IIF([Sales] <= 1000, 'Medium', 'High')) -> Option D

4. Quick Check:

   Nested IIF handles ranges correctly [OK]

Hint: Use nested IIF for multiple range conditions [OK]

Common Mistakes:

• Using CASE for range conditions
• Writing ELSEIF instead of ELSE IF
• Overlapping or missing conditions