Type conversion functions in Tableau - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ dax_lod_result

intermediate

Output of INT() conversion in Tableau

What is the output of the following Tableau calculated field?

INT("123.99")

Assume the input is a string and INT() converts it to an integer.

Tableau

INT("123.99")

A 123

B 124

C 123.99

D Error: Cannot convert string with decimal to INT

💡 Hint

INT() truncates decimal parts after converting to number.

INT() converts the string to a number and truncates the decimal part, so '123.99' becomes 123.

❓ visualization

intermediate

Visualizing type conversion impact on data

You have a dataset with a field 'Sales' stored as string values like '1000', '2000', '3000'. You want to create a bar chart showing total sales.

Which Tableau calculated field should you use to correctly sum sales as numbers?

A SUM(STR([Sales]))

B SUM([Sales])

C SUM(INT([Sales]))

D SUM(FLOAT([Sales]))

💡 Hint

Sales values have decimals possible, so use a conversion that supports decimals.

FLOAT() converts string to decimal numbers, allowing SUM() to add them correctly. INT() would truncate decimals, STR() converts to string (no sum), and SUM([Sales]) sums strings causing error.

🧠 Conceptual

advanced

Understanding type conversion errors in Tableau

Which of the following scenarios will cause a type conversion error in Tableau when using INT() or FLOAT() functions?

A Converting a number 123 to INT()

B Converting a string 'abc123' to INT()

C Converting a string '123.45' to FLOAT()

D Converting a string '1000' to FLOAT()

💡 Hint

Think about what strings can be converted to numbers.

Strings with non-numeric characters like 'abc123' cannot be converted to numbers, causing errors. Other options are valid conversions.

❓ data_modeling

advanced

Choosing correct type conversion for date calculations

You have a string field 'OrderDate' in format '2023-06-15'. You want to calculate the number of days since this date.

Which Tableau calculated field correctly converts 'OrderDate' to a date type for this calculation?

A DATEDIFF("day", STR([OrderDate]), TODAY())

B DATEDIFF("day", INT([OrderDate]), TODAY())

C DATEDIFF("day", DATE([OrderDate]), TODAY())

D DATEDIFF("day", FLOAT([OrderDate]), TODAY())

💡 Hint

Dates must be converted to date type, not numbers or strings.

DATE() converts string to date type. INT() and FLOAT() convert to numbers causing errors. STR() keeps string type, invalid for date calculations.

🔧 Formula Fix

expert

Debugging type conversion in nested calculations

Given the Tableau calculated field:

IF INT([Score]) > 50 THEN "Pass" ELSE "Fail" END

Which issue will cause this calculation to fail or produce incorrect results?

Tableau

IF INT([Score]) > 50 THEN "Pass" ELSE "Fail" END

A If [Score] contains null or non-numeric strings, INT() will cause an error

B Comparison operator '>' is invalid in Tableau calculated fields

C The ELSE clause is missing a return value causing syntax error

D INT() converts decimals correctly, so no issues expected

💡 Hint

Consider what happens if input is not a clean number string.

INT() fails if input is null or contains non-numeric characters, causing calculation errors. ELSE clause and '>' operator are valid syntax.

Practice

1. Which Tableau function converts a string like '123' into an integer?

easy

A. FLOAT()

B. STR()

C. DATE()

D. INT()

Solution

1. Step 1: Understand the input type

   The input is a string '123' which represents a number but is stored as text.

2. Step 2: Choose the function to convert string to integer

   INT() converts a string that looks like a number into an integer type.

3. Final Answer:

   INT() -> Option D

4. Quick Check:

   String '123' to number = INT() [OK]

Hint: Use INT() to convert numeric strings to whole numbers [OK]

Common Mistakes:

• Using STR() which converts numbers to strings
• Using DATE() which converts to date format
• Using FLOAT() when integer is needed

2. Which of the following is the correct syntax to convert a date string '2023-06-01' to a date in Tableau?

easy

A. FLOAT('2023-06-01')

B. DATE('2023-06-01')

C. INT('2023-06-01')

D. STR('2023-06-01')

Solution

1. Step 1: Identify the data type to convert to

   The string '2023-06-01' represents a date, so we want to convert it to a date type.

2. Step 2: Use the DATE() function for conversion

   DATE() converts a string formatted as a date into a Tableau date type.

3. Final Answer:

   DATE('2023-06-01') -> Option B

4. Quick Check:

   Convert date string to date = DATE() [OK]

Hint: Use DATE() to convert date strings to date type [OK]

Common Mistakes:

• Using STR() which converts to string, not date
• Using INT() or FLOAT() which cause errors on date strings
• Missing parentheses in function call

3. What is the result of this Tableau calculation?

INT('45.67')

medium

A. Error

B. 45

C. 46

D. 45.67

Solution

1. Step 1: Analyze the input string

   The string '45.67' represents a decimal number.

2. Step 2: Understand INT() behavior on decimal strings

   INT() expects a string representing an integer; passing a decimal string causes an error in Tableau.

3. Final Answer:

   Error -> Option A

4. Quick Check:

   INT('45.67') causes error [OK]

Hint: INT() only converts strings representing whole numbers [OK]

Common Mistakes:

• Expecting an error on decimal strings
• Thinking INT() rounds up to 46
• Confusing truncation with keeping decimals

4. You wrote this Tableau formula but get an error:

FLOAT('abc')

What is the likely cause?

medium

A. The string 'abc' cannot convert to a number

B. FLOAT() requires a date input

C. Missing quotation marks around abc

D. FLOAT() only works on integers

Solution

1. Step 1: Check the input string

   The string 'abc' contains letters, not numeric characters.

2. Step 2: Understand FLOAT() conversion rules

   FLOAT() converts strings representing numbers to decimal numbers; non-numeric strings cause errors.

3. Final Answer:

   The string 'abc' cannot convert to a number -> Option A

4. Quick Check:

   Non-numeric string to FLOAT() = Error [OK]

Hint: Only numeric strings convert with FLOAT() [OK]

Common Mistakes:

• Thinking FLOAT() works on any string
• Assuming FLOAT() needs date input
• Forgetting quotes around strings

5. You have a field [Sales] stored as string values like '1000', '2000', and '3000'. You want to calculate the average sales as a number. Which formula correctly converts and averages these values?

hard

A. INT(AVG([Sales]))

B. AVG(STR([Sales]))

C. AVG(INT([Sales]))

D. AVG(DATE([Sales]))

Solution

1. Step 1: Convert string sales to numbers before averaging

   Since [Sales] is string, convert each value to integer using INT() first.

2. Step 2: Apply AVG() on converted integers

   AVG(INT([Sales])) calculates the average of numeric sales correctly.

3. Final Answer:

   AVG(INT([Sales])) -> Option C

4. Quick Check:

   Convert then average = AVG(INT()) [OK]

Hint: Convert strings to numbers before aggregation [OK]

Common Mistakes:

• Averaging strings directly causes errors
• Converting after averaging strings is invalid
• Using DATE() on numeric strings