Documenting Excel formulas is an important step in the auditing of spreadsheets. Presented here is a new technique to aid in that process.

The utility of the recently added FORMULATEXT, ISFORMULA and TEXTJOIN functions is sometimes underestimated. The FORMULATEXT and ISFORMULA functions were introduced with Excel 2013 and the TEXTJOIN function is available only the Excel 2016 version which comes with an Office 365 subscription. In the technique demonstrated in this article, al three of these functions are used in a single formula. For the result, see the following figure:

The key formula (in cell K1) is

=TEXTJOIN(CHAR(10),TRUE,IF(ISFORMULA(fRange),ADDRESS(ROW(fRange),COLUMN(fRange))&”:”&FORMULATEXT(fRange),””))

To understand how this formula works, lets break it down into its main parts.

ADDRESS(ROW(fRange),COLUMN(fRange)) returns an array of cell addresses for the desired range (in this case, fRange, which is E1:F13).

FORMULATEXT(fRange) returns an array of formulas for that range.

When these two formulas are concatenated with a colon, you get an array that looks like this.

{#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;#N/A,#N/A;”$E$13:=SUM(E1:E12)”,”$F$13:=SUM(F1:F12)”}

In this example, formulas only exist in cells E13 and F13, with the rest of the array elements as #N/A. When the ISFORMULA function is applied to the range is question, the result is

{FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;FALSE,FALSE;TRUE,TRUE}

So, the final array created by the IF function looks like this.

{“”,””;””,””;””,””;””,””;””,””;””,””;””,””;””,””;””,””;””,””;””,””;””,””;”$E$13:=SUM(E1:E12)”,”$F$13:=SUM(F1:F12)”}

When this array is processed by the TEXTJOIN function, it affords a string of formulas with their corresponding cell locations.

Note that this technique can also be used with non-contiguous ranges. Since the TEXTJOIN function can use additional arrays as arguments (see https://dhexcel1.wordpress.com/2017/05/21/excel-short-and-sweet-tip-15-using-textjoin-with-non-contiguous-ranges-by-david-hager/ ), the same array formula used in the 3^{rd} argument of this TEXTJOIN example can be used in subsequent arguments, provided that the desired ranges for those arrays are different.

You can download the example file here.