The foreach loop will allow you to repeat a series of commands for multiple variables/values. In the table below, are some of the possible constructions. The first one is the most useful, you just type the columns directly into the command. The second one is useful if you're not running the commands on variables in the dataset (for example, maybe you want to open a series of files).
The actual code will look something like this (notice that in the code, var is preceded by a grave accent (`) and followed by an apostrophe(')):
foreach var of varlist name gender var* {
replace `var'="none" if
`var'==""
}
When the code runs, each instance of `var' will be replaced by the given variables. For example, what runs in Stata will be
replace name="none" if name==""
replace gender="none" if name==""
replace var1="none" if name==""
replace var2="none" if name==""
...
This makes it convenient to repeat the same commands multiple times.
| command | notes |
|---|---|
| foreach var of varlist name gender var* {...} | |
| foreach var of local vars {...} | must define local vars before calling |
| forvalues x=1/1000 {...} | loops through |
| foreach var in "var1" "var2" "var3" {...} |