Extract specific letters from a string of text

Question

Hello,
I have an idea that I would like to implement into Numbers but I'm not quite sure how to do it, or even if it is possible. What I would like to do is replace a multitude of checkboxes with one cell. In that one cell I will have a string of text, with a letter representing a condition. From this one cell, I would like to be able to extract a certain letter into its own cell and then hide the multitude of cells.
My idea is to eventually just be able to type the conditions into a single cell, extract the letter of the certain condition into another cell, and then extract that information into another table, all the while hiding all of the auxiliary columns in the original table. Because it would be much easier and prettier to simply type a bunch of letters into one box instead of having to check a bunch of boxes, no?
For example Left Header Row 1 would contain the letters BMRT. Column A would return a "FALSE" value, while Column B would return "B" or "TRUE." Columns C through L return "FALSE," etc.
In Left Header Row 2 we would have the string AJQTVZ, for instance. Column A would return "A" (or "TRUE"), and Columns B through I would return "FALSE."
Is it possible to write such a formula? Or is there an easier way to be thinking about this problem?

Answer 1

Let's start with the easy part.
Cells on a Numbers table can contain data entered directly, or can contain a formula. They can't contain both. That means you cannot 'type the conditions into a single cell' in column A ("the left header" cell) AND have a formula which sets that cell to TRUE if the typed in data contains an "A".
There's no problem doing this using column A as the key holder and columns B:Z to hold the TRUE/FALSE results, staring in both cases on row 2.
Here's an example
The column header cells (row 1) contain the letter corresponding to that column.
The row header cells (starting at row 2) contain the 'bunch of letters' you describe. Note (A4) that the letters do not have to be entered in any particular order, and that extraneous characters (eg. a space) are ignored.
The formula shown is entered B2, and filled down and right from there.
=IFERROR(FIND(B$1,$A2)>0,FALSE)
FIND returns the position of the first occurrence of the target string (in this case, the single letter at the top of the column) in the search string, then compares that with the value zero. For any letter that is included in the search string, the find value will be at least 1, so the comparison will return TRUE. If the target letter is not found, FIND returns an error. IFERROR traps this and returns FALSE.
Since the target depends on the letter at the top of the column, all that's needed to extend the range of possible letters to the full alphabet is to enter an A in cell B1, then run through the alphabet A to Z, with Z in cell AA1.
Depending what you want to do with the TRUE or FALSE values in these 26 columns, it may be possible to skip the auxiliary column step and use a formula similar to the one above as the condition argument of an IF(condition,do-if-true,do-if-false) statement.
Regards,
Barry