Information functions in Grid by Zaweba: checking cells

Some functions calculate. Others ask questions. The information family in Grid by Zaweba is the second kind: 22 functions that tell you what a cell contains, what kind of value it is, whether it holds a formula, and where it sits in the workbook. On their own they rarely appear in a finished report, but they're behind many of the formulas that make a sheet robust.

The IS functions

ISNUMBER, ISBLANK, ISERROR and their relatives each return TRUE or FALSE. They're most useful inside an IF. A formula that divides by a cell can first check whether that cell is a number; a line on an invoice can stay blank until a quantity has been entered; a summary can count how many rows still have an error that needs fixing.

ISNUMBER is the quiet hero for data that came from somewhere else. Figures pasted from a website or a PDF often arrive as text that only looks like numbers. A helper column with ISNUMBER shows straight away which cells are real numbers and which aren't, and conditional formatting can colour the odd ones out so you spot them as you scroll.

ISBLANK is literal. A cell holding a formula that returns empty text isn't blank to it. When you need "looks empty", test whether the cell equals empty text instead.

Asking about values and errors

TYPE returns a number that says what kind of value a cell holds: number, text, logical value, error or array. ERROR.TYPE returns a number for each kind of error, which lets a formula react differently to a missing lookup and a division by zero. That's a finer tool than IFERROR, which treats every error the same.

Formulas about formulas

ISFORMULA tells you whether a cell contains a formula or a typed value. In a template where some cells should always be calculated, conditional formatting with ISFORMULA can highlight any cell where someone has typed over the formula with a fixed number, which is one of the most common ways a shared sheet goes wrong.

FORMULATEXT shows the formula from another cell as text. It's handy for documentation, training sheets and checking work: put FORMULATEXT next to a key result and the reader can see both the answer and how it was reached. For a view of every formula at once, Show Formulas on the ribbon swaps values for formulas across the sheet.

Where am I?

SHEET returns the number of a sheet and SHEETS counts the sheets in a reference or in the workbook. They're useful on summary sheets that roll up a sheet per month or per branch. CELL returns details about a cell, such as its address or format, and INFO returns details about the working environment. Both are mostly for advanced templates, but they're there when a formula needs to know about its own surroundings.

Putting them to work

A practical pattern for any sheet that other people fill in is a small check column. Use ISNUMBER for quantities, ISBLANK for required fields and ISERROR for lookups, and combine them with AND into one TRUE or FALSE per row. Filter on FALSE to see exactly which rows need attention. Data validation stops many bad entries at the door; the check column catches the ones that slipped in before the rules existed, alongside Circle Invalid Data.

Keep the checks visible while you build, then hide the column or move it to the side once the sheet settles down. Information functions in Grid by Zaweba follow the usual spreadsheet behaviour, so a check you build here works the same way when the workbook is opened as .xlsx elsewhere.