# ISERROR Function in Excel

🌟 Part 1: Introduce 🌟

Definition: The ISERROR function is a built-in function in Microsoft Excel that allows users to check whether a specified cell contains an error value. It returns a Boolean value, TRUE if the cell has an error, and FALSE if it does not.

Purpose: The primary purpose of the ISERROR function is to help users handle and manage errors in their Excel worksheets. Using the ISERROR function, you can verify if a cell contains an error before further calculations or operations, preventing unwanted errors from propagating through your formulas.

Syntax & Arguments:

syntax
`=ISERROR(value) `

Explain the Arguments in the function:

• Value: This argument represents the cell or formula you want to check for an error. It can be a single-cell reference or a procedure that returns a value. The ISERROR function will evaluate the specified value and return TRUE if it contains an error, such as #VALUE!, #REF!, #DIV/0!, etc. Otherwise, it will return FALSE.

Return value: The ISERROR function returns a Boolean value (TRUE or FALSE), indicating whether the specified cell or formula contains an error. It will return TRUE if the value has an error and FALSE if it does not.

Remarks:

• The ISERROR function is handy when handling various errors in your Excel formulas, ensuring that your calculations are accurate and error-free.
• It is often combined with the IF function to create conditional statements that perform different actions based on whether a cell contains an error.

🌟 Part 2: Examples of ISERROR Function 🌟

1️⃣ Example 1: Checking Division by Zero

ABCD
1Value1Value2ResultError Check
2102=A2/B2=IF(ISERROR(C2), “Error”, C2)
3150=A3/B3=IF(ISERROR(C3), “Error”, C3)
484=A4/B4=IF(ISERROR(C4), “Error”, C4)

Explanation: In this example, we have a table with numeric values in columns A and B. We want to perform division on each row and calculate the result in column C using the formula =A2/B2. However, dividing by zero (as in cell B3) will result in an error. The ISERROR function is used in column D to check for errors in column C. If an error is found, it will display “Error”; otherwise, it will display the result from column C.

2️⃣ Example 2: Handling Invalid Data with VLOOKUP

ABCD
1IDNameDepartmentDepartment Lookup
2101JohnSales=VLOOKUP(A2, B2:C4, 2, FALSE)
3102SarahMarketing=VLOOKUP(A3, B2:C4, 2, FALSE)

Explanation: In this example, we have a table with employee IDs in column A, their corresponding names in column B, and departments in column C. We use the VLOOKUP function to find the department for each employee based on their ID. However, if the ID is not found in the lookup table (B2:C4), the VLOOKUP function will return an error. The ISERROR function is used in cell D4 to check for errors in the VLOOKUP result. If the ID is not found, it will display “Not Found”; otherwise, it will display the department.

3️⃣ Example 3: Checking Errors in CONCATENATE Function

ABC
1FirstLastFull name
2JohnDoe=A2&B2
3Jane25=A3&B3
4MikeSmith=IF(ISERROR(A4&B4), “Error”, A4&B4)

Explanation: In this example, we have a table with first names in column A and last names in column B. We use the CONCATENATE function to combine the first and last names to form the complete terms in column C. However, the CONCATENATE function will return an error when concatenating a text string (A4) with a numeric value (B4). The ISERROR function in cell C4 is used to check for errors in the concatenation. If an error is found, it will display “Error”; otherwise, it will display the concatenated full name.

4️⃣ Example 4: Checking Errors in AVERAGE Function

ABC
1Value1Value2Average Result
21020=AVERAGE(A2:B2)
315ABC=IF(ISERROR(AVERAGE(A3:B3)), “Error”, AVERAGE(A3:B3))
4812=AVERAGE(A4:B4)

Explanation: In this example, we have a table with numeric values in columns A and B. We want to calculate the average of each row in column C using the AVERAGE function. However, the AVERAGE function will return an error if any values in a row are invalid (e.g., non-numeric). We use the ISERROR function with IF to handle these errors gracefully and display “Error” in cell C3 when an invalid data type is encountered.

5️⃣ Example 5: Handling Errors in Nested IF Statements

ABCD
285Pass=IF(ISERROR(IF(A2>=80, “A”, IF(A2>=70, “B”, IF(A2>=60, “C”, IF(A2>=50, “D”, “F”))))), “Invalid Score”, IF(A2>=80, “A”, IF(A2>=70, “B”, IF(A2>=60, “C”, IF(A2>=50, “D”, “F”)))))
395Pass=IF(ISERROR(IF(A3>=80, “A”, IF(A3>=70, “B”, IF(A3>=60, “C”, IF(A3>=50, “D”, “F”))))), “Invalid Score”, IF(A3>=80, “A”, IF(A3>=70, “B”, IF(A3>=60, “C”, IF(A3>=50, “D”, “F”)))))
4ABCPass=IF(ISERROR(IF(A4>=80, “A”, IF(A4>=70, “B”, IF(A4>=60, “C”, IF(A4>=50, “D”, “F”))))), “Invalid Score”, IF(A4>=80, “A”, IF(A4>=70, “B”, IF(A4>=60, “C”, IF(A4>=50, “D”, “F”)))))

Explanation: In this example, we have a table with student scores in column A. We want to determine the grade and status (Pass/Fail) based on the score using nested IF statements. However, if the score is not numeric, the nested IF statements will return an error. When encountering an invalid data type, we use the ISERROR function with IF to check for errors and display an “Invalid Score” in cell D4.

6️⃣ Example 6: Checking Errors in LOOKUP Function

ABCD
1ProductPriceQuantityTotal
2Apple2.510=B2*C2
3BananaABC20=IF(ISERROR(LOOKUP(A3, B2:B3, C2:C3)), “Error”, LOOKUP(A3, B2:B3, C2:C3))
4Orange1.815=B4*C4

Explanation: In this example, we have a table with product names in column A, their corresponding prices in column B, and quantities in column C. We want to calculate the total cost of each product in column D using the formula =B2*C2. However, if the price of a product is not a numeric value (e.g., “ABC” in cell B3), the calculation will result in an error. We use the ISERROR function with IF to handle these errors gracefully and display “Error” in cell D3 when an invalid data type is encountered.

7️⃣ Example 7: Handling Errors in INDEX-MATCH Function

ABCD
1IDNameAgeName Lookup
2101John25=INDEX(B2:B4, MATCH(A2, A2:A4, 0))
3102Sarah30=INDEX(B2:B4, MATCH(A3, A2:A4, 0))

Explanation: In this example, we have a table with employee IDs in column A, their corresponding names in column B, and ages in column C. We want to find each employee’s name based on their ID using the INDEX-MATCH function. However, the INDEX-MATCH function will return an error if the ID is not found in the lookup range (A2:A4). The ISERROR function is used in cell D4 to check for errors in the INDEX-MATCH result. If the ID is not found, it will display “Not Found”; otherwise, it will display the employee’s name.

8️⃣ Example 8: Checking Errors in SUMIF Function

ABC
1NameScoreTotal Score
2John85=SUMIF(B2:B4, A2, B2:B4)
3Sarah95=SUMIF(B2:B4, A3, B2:B4)

Explanation: In this example, we have a table with student names in column A and their corresponding scores in column B. We want to calculate the total score of each student using the SUMIF function. However, if the student’s name is not found in the lookup range (B2:B4), the SUMIF function will return an error. The ISERROR function is used in cell C4 to check for errors in the SUMIF result. If the name is not found, it will display “Not Found”; otherwise, it will display the total score.

9️⃣ Example 9: Handling Errors in TEXT Function

ABC
1DateFormatFormatted Date
244258d/m/y=TEXT(A2, B2)
344259y/m/d=TEXT(A3, B3)
4XYZd-m-y=IF(ISERROR(TEXT(A4, B4)), “Invalid Date”, TEXT(A4, B4))

Explanation: In this example, we have a table with date values in column A and their corresponding date formats in column B. We want to format the dates as per the specified format using the TEXT function. However, if the date value is not a valid numeric date (e.g., “XYZ” in cell A4), the TEXT function will return an error. The ISERROR function in cell C4 checks for errors in the TEXT function. If an error is found, it will display “Invalid Date”; otherwise, it will display the formatted date.

🔟 Example 10: Checking Errors in INDEX and CHOOSE Functions

ABCD
1IndexValue1Value2Result
21AppleOrange=INDEX(B2:C2, A2)
33Banana25=IF(ISERROR(INDEX(B3:C3, A3)), “Error”, INDEX(B3:C3, A3))
42ABCPear=INDEX(B4:C4, A4)

Explanation: In this example, we have a table with index values in column A and corresponding values in columns B and C. We use the INDEX function to retrieve the value at the specified index. However, if the index is not within the range (e.g., 3 in cell A3), the INDEX function will return an error. The ISERROR function in cell D3 checks for errors in the INDEX function. If an error is found, it will display “Error”; otherwise, it will display the value.

🌟 Part 3: Tips and Tricks 🌟

• Combine the ISERROR function with the IF function to handle and manage errors effectively in your Excel worksheets.
• Use the ISERROR function in complex formulas or functions to ensure accurate calculations and prevent errors from propagating further.
• When working with large datasets or complex formulas, the ISERROR function can be extremely helpful in identifying and resolving errors quickly.
• Regularly check your formulas and use the ISERROR function during data validation to maintain data accuracy and reliability in your Excel spreadsheets.

By utilizing the ISERROR function and understanding its applications, you can create more robust and reliable Excel spreadsheets with fewer errors.