Counting zeros

[Belinda Foster]

Is there a quick way to count the zeros in a number? For example, 500 000 has five zeros.

[Nick Cox]

The precise problem in Stata I guess to be for a numeric variable holding integers only.

Here is one approach. Documented at http://www.stata-journal.com/sjpdf.h...iclenum=dm0056

clear
input numeric
42
666
10
100
1000
10000
end

tostring numeric, generate(string)
gen nzero = length(string) - length(subinstr(string, "0", "", .))

list, sep(0)

     +--------------------------+
     | numeric   string   nzero |
     |--------------------------|
  1. |      42       42       0 |
  2. |     666      666       0 |
  3. |      10       10       1 |
  4. |     100      100       2 |
  5. |    1000     1000       3 |
  6. |   10000    10000       4 |
     +--------------------------+

If you have a string variable instead, things will be easier. If you want to do this with fractional parts, that's messier.