# ISLOGICAL Function

Published on :

21 Aug, 2024

Blog Author :

N/A

Edited by :

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Reviewed by :

Dheeraj Vaidya

## What Is ISLOGICAL Function In Excel?

The

ISLOGICALfunction in Excel is a built-inInformationfunction and one of theISExcel functions. It accepts a value and checks if the specified value is a logical value,TRUEorFALSE. The function output isTRUEif the given value is logical. Otherwise, it returnsFALSE.Users can utilize the

ISLOGICALfunction during data validation and formatting, error checking, and filtering based on logicalTRUEsandFALSEs.

For example, the following dataset contains a list of values.

The task is to determine which of the given values are logical values, **TRUE **or **FALSE** and display the output in the corresponding cells in column B.

Then, we can apply the **ISLOGICAL formula **in each target cell to achieve the required data.

In the above **ISLOGICAL formula **example, the **ISLOGICAL()** accepts the reference to the cell containing the value we must check in the corresponding row.

The **ISLOGICAL **function then returns **TRUE** if the value in the specified cell is a logical **TRUE **or **FALSE**. Otherwise, the function returns **FALSE** as the output.

Furthermore, the **ISLOGICAL function for both Mac and PC **works according to the above mentioned logic.

##### Table of contents

- The
**ISLOGICAL**function accepts a value and returns**TRUE**if the supplied value is logical. Otherwise, it returns**FALSE**. The input can be a valid value, logical value, error value, or a formula returning a value or logical value. - Users can utilize the
**ISLOGICAL**Excel function for checking formulas for potential errors, data validation, and sorting data based on logical values. - The
**ISLOGICAL**Excel function accepts one mandatory argument value,**value**. - While we can apply the
**ISLOGICAL**Excel function as a standalone function, using it with other inbuilt functions, such as**IF**and other**IS**Excel functions, yields fruitful outcomes.

### Syntax

The syntax to apply while **using ISLOGICAL function** is the following:

Where,

**value**: The data we aim to check if it is a logical**TRUE**or**FALSE**.

The argument in the **ISLOGICAL **function is mandatory, and it can be a logical value, text, number, error value, cell reference, or a range referring to these values.

### How To Use ISLOGICAL Excel Function?

We can utilize the **ISLOGICAL **function in two ways:

**Access the function from the Excel ribbon.****Enter the function into the worksheet manually.**

#### Method #1 – Access The Function From The Excel Ribbon

Choose a cell to calculate and display the output - The **Formulas** tab - The **More Functions **down arrow - The **Information **function group right arrow - **ISLOGICAL **function.

The **Function Arguments** window will be opened. Update the argument in the **Value** field.

Finally, clicking **OK** in the **Function Arguments** window will help us view the **ISLOGICAL **function return value in the target cell.

#### Method 2 – Enter The Function Into The Worksheet Manually

- Choose a cell to display the output.
- Type
**=ISLOGICAL(**in the cell. - Enter the argument as a value, cell reference, or formula and close the brackets.
- Press
**Enter**to view the**ISLOGICAL()**output.

Please note that the above methods work for the **ISLOGICAL function for both Mac and PC**.

### Examples

The following **ISLOGICAL **function examples will help utilize the function effectively.

#### Example #1

The following dataset contains a list of values and their data types.

The aim is to determine if the values in column A are logical or Boolean values and display the output as **TRUE **or **FALSE** in the corresponding cells in column C.

Then, here is how to obtain the required data **using ISLOGICAL function **in each target cell.

**Step 1: **Choose cell C2, enter the **ISLOGICAL **function, and press **Enter**.

**=ISLOGICAL(FALSE)**

Supplying the argument value as a reference to the cell containing the value we aim to check in the **ISLOGICAL **function will give the same output.

*=ISLOGICAL(A2)*

**Step 2: **Using the Excel fill handle, update the **ISLOGICAL **function in the remaining target cells.

On the other hand, when we supply a Boolean value in double quotes to the **ISLOGICAL()** as the argument value, the function treats it as a text value. Hence, the function returns **FALSE**, as depicted below:

#### Example #2

The dataset below contains different formula outputs in column A.

The task is to find out the formula outputs that are logical values and display the result in column C.

Then, here is how to apply the **ISLOGICAL **function in each target cell to achieve the desired outcome.

**Step 1: **Choose cell C2, enter the **ISLOGICAL **function**, **and press **Enter**.

*=ISLOGICAL(A2)*

**Step 2: **Using the fill handle, implement the **ISLOGICAL()** in the remaining target cells.

Let us check the cell C9 formula to understand the logic.

First, the **ROUND()** returns the value after rounding off the input value **544.954** to two decimal places, which is **544.95**. Next, the **ISLOGICAL()** accepts the **ROUND()** return value as the input and checks whether it is a logical value. Since the value **544.95 **is not a logical value, the **ISLOGICAL() **output is **FALSE**.

#### Example #3

Let us see how to use the **ISLOGICAL **function for data validation.

The dataset below contains comments in column A.

The aim is to update whether the comment is true or false in column B. Also, we can only enter **TRUE **or **FALSE** in column B cells. Otherwise, Excel must warn us to enter only **TRUE **or **FALSE **in the target cells.

Then, here is how to use the **ISLOGICAL **function with the **Excel Data Validation** feature to achieve the desired outcome.

**Step 1: **Choose cells B2:B5 and select **Data **- **Data Validation **- **Data Validation**.

The **Settings **tab within the **Data Validation **window opens. Click the **Allow** field drop-down button to choose **Custom** from the drop-down list.

Next, update the following **ISLOGICAL()** formula in the **Formula** field.

*=ISLOGICAL(B2:B5)*

After that, click the **Input Message** tab to open it.

**Step 2: **Update the **Title **and **Input message **fields to guide the user to enter the required data in the chosen cells.

Next, click the **Error Alert** tab to access it.

**Step 3: **Update the **Title **and **Error message **fields with the data to show as a warning message to the user when they enter a value other than logical values in the chosen cells.

Click **OK** to exit the **Data Validation **window.

The input message is visible since the required cells are chosen.

**Step 4: **Enter the appropriate logical value in cell B2 and press **Enter**.

Next, assume we enter “**No**” instead of the required **FALSE** value in cell B3.

On pressing **Enter**, Excel will show the **Error Message** box, stating to enter a Boolean value, **TRUE** or **FALSE**.

**Step 5: **Clicking **Retry** in the **Error Message **box will insert the cursor into cell B3, enabling us to update the required logical value in the specific cell.

Finally, press **Enter **and continue entering the appropriate logical values in the remaining target cells.

Since we used the **ISLOGICAL **function in the **Formula **field in the **Data Validation** window, the function ensures that we can only enter the logical values in the chosen cells. Otherwise, Excel asks us to update the appropriate logical values in the specific cell.

### Important Things To Note

- Ensure to supply an error-free
**value**argument value to the**ISLOGICAL**function in Excel. Otherwise, the function return value will be the Excel**#VALUE!**error value. - The
**ISLOGICAL**Excel function does not consider**1**and**0**as logical**TRUE**and**FALSE**. - The
**ISLOGICAL**Excel function does not consider**TRUE**or**FALSE**supplied in double quotes as logical values.

### Frequently Asked Question (FAQs)

**1. Give an ISLOGICAL Excel function in VBA example.**

The **ISLOGICAL** Excel function in VBA example is as follows:

The following dataset lists values in column A.

We can check if the values are logical values using the IsLogical method in Excel VBA and display the output in column B.

Step 1: Let the sheet containing the source dataset be the active sheet, and press Alt + F11 to open the VBA Editor.

Step 2: Choose the required VBAProject and select Module from the Insert tab.

A new module window opens.

Step 3: Type in the VBA code to apply the ISLOGICAL() in all the target cells.

Step 4: Press the play icon in the menu to execute the code.

Now, when we open the active sheet, we will see the ISLOGICAL() applied in every target cell.

The ISLOGICAL() in each target cell accepts the input value in the corresponding row and checks whether the value is logical. If the value is logical, the function returns TRUE, else FALSE.

**2. What are the common mistakes when using ISLOGICAL() in Excel formula?**

The common mistakes when using **ISLOGICAL()** in Excel formula are as follows:

• The supplied argument value is not proper.

• Confusing the **ISLOGICAL()** with other **IS **Excel functions.

• Expecting the **ISLOGICAL() **to return **TRUE** for values assumed to be logical values.

**3. Why isn’t my ISLOGICAL working?**

Your **ISLOGICAL** isn’t working because of the following reasons:

• The function name is incorrect.

• The supplied argument value is an invalid cell reference, value, or formula.

• The formula supplied as input to the **ISLOGICAL()** is incorrect and contains errors.

### Download Template

This article must be helpful to understand the **ISLOGICAL Function**, with its formula and examples. You can download the template here to use it instantly.

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