IS functions: ISBLANK, ISERR, ISERROR, ISLOGICAL, ISNA, ISNONTEXT, ISNUMBER, ISREF, ISTEXT

What is IS function in Excel?

IS functions, ISBLANK, ISERR, ISERROR, ISLOGICAL, ISNA, ISNONTEXT, ISNUMBER, ISREF, ISTEXT are under the Information functions in Microsoft Excel.

Each of these functions, referred to collectively as the IS functions, checks the specified value and returns TRUE or FALSE depending on the outcome. For example, the ISBLANK function returns the logical value TRUE if the value argument is a reference to an empty cell; otherwise it returns FALSE.

You can use an IS function to get information about a value before performing a calculation or other action with it. For example, you can use the ISERROR function in conjunction with the IF function to perform a different action if an error occurs:

= IF( ISERROR(A1), “An error occurred.”, A1 * 2)

This formula checks to see if an error condition exists in A1. If so, the IF function returns the message “An error occurred.” If no error exists, the IF function performs the calculation A1*2.

Syntax of IS functions

ISBLANK(value)

ISNONTEXT(value)

ISNUMBER(value)

ISREF(value)

ISTEXT(value)

ISERR(value)

ISERROR(value)

ISLOGICAL(value)

ISNA(value)

The IS function syntax has the following argument:

value: The value that you want tested. The value argument can be a blank (empty cell), error, logical value, text, number, or reference value, or a name referring to any of these.

Worked Example: Excel Data validation allow numbers only

Function	Returns TRUE if
ISBLANK	Value refers to an empty cell.
ISNA	Value refers to the #N/A (value not available) error value.
ISNONTEXT	Value refers to any item that is not text. (Note that this function returns TRUE if the value refers to a blank cell.)
ISERR	Value refers to any error value except #N/A.
ISERROR	Value refers to any error value (#N/A, #VALUE!, #REF!, #DIV/0!, #NUM!, #NAME?, or #NULL!).
ISREF	Value refers to a reference.
ISTEXT	Value refers to text.
ISLOGICAL	Value refers to a logical value.
ISNUMBER	Value refers to a number.

IS functions explanation

The value arguments of the IS functions are not converted. Any numeric values that are enclosed in double quotation marks are treated as text. For example, in most other functions where a number is required, the text value “19” is converted to the number 19. However, in the formula ISNUMBER(“19”), “19” is not converted from a text value to a number value, and the ISNUMBER function returns FALSE.
The IS functions are useful in formulas for testing the outcome of a calculation. When combined with the IF function, these functions provide a method for locating errors in formulas (see the following examples).

Worked Example: Check if range contains a value not in another range in Excel

Examples IS functions

Example 1

Steps to follow:

1. Open a new Excel worksheet.

2. Copy data in the following table below and paste it in cell A1

Note: For formulas to show results, select them, press F2 key on your keyboard and then press Enter.

You can adjust the column widths to see all the data, if need be.

Formula	Description	Result
=ISLOGICAL(TRUE)	Checks whether TRUE is a logical value	TRUE
=ISLOGICAL(“TRUE”)	Checks whether “TRUE” is a logical value	FALSE
=ISNUMBER(4)	Checks whether 4 is a number	TRUE
=ISREF(G8)	Checks whether G8 is a valid reference	TRUE
=ISREF(XYZ1)	Checks whether XYZ1 is a valid reference	FALSE

Worked Example: Highlight blank cells in Excel

Example 2