Determining the last row in a single column

Question

I have a sheet with data in cols A through H.

I need to determine the last row in column A that contains data (it's all contiguous - no gaps in the data/rows).

There is also data in the other columns that have more rows of data than column A, so I need to isolate only column A. (And/or just a range within col A).

I can do this on the spreadsheet level using

=COUNTA(A2:A100)

However in all of my researching for a Google Apps Script solution, all I seem to find are requirements to perform multiple functions encompassing dozens of lines of code - including plenty of i++ stuff... Which I could do less complexly via offsetting directly from A1.

Is there possibly a column-specific way of modifying this method?

var aLast = ss.getDataRange().getNumRows();

If a convoluted process is what is required, then so be it. But I find it difficult to imagine (and even more difficult to find!) a simpler solution.

Does anyone care to enlighten me (or pop my bubble)?

Answer 1

How about using a JavaScript trick?

var Avals = ss.getRange("A1:A").getValues();
var Alast = Avals.filter(String).length;

I borrowed this idea from this answer. The Array.filter() method is operating on the Avals array, which contains all the cells in column A. By filtering on a native function's constructor, we get back only non-null elements.

This works for a single column only; if the range contains multiple columns,then the outcome of filter() will include cells from all columns, and thus be outside the populated dimensions of the range.