Often I use locals to calculate something (such as the mean of a variable for a specific group) and use this in a loop (say, over groups or over years). If you, for example, want to calculate the share of observations that belong to one group (say:
female==1), you could simply write
quietly count if female==1 local num_fem=r(N)' quietly count local share_fem=num_fem'/r(N)' di "The share of women in the sample is: `share_fem'"
which might then return something like:
The share of women in the sample is: 0.48239049
To make the output slightly better to read, Stata allows to format the format of locals. To cut the local
share_fem to only two decimals, for example, we could add the following line:
: display %9.3g `share_fem''")
Or, alternatively, replace the last line with
di "The share of women in the sample is: " %9.3g `share_fem'
Pro-tip: use the format
%09.3g if you want to use a 0 before the period sign.