Looping over many names which don't have rules - stata

Question

When there are just few names, looping in Stata is easy.
Also, when there is a rule as to how the names change (e.g. increment) I can do the following:
forval i = 1/5 {
...
}
However, there are cases where i have hundreds of names that I need to loop over, which don't have rules of increment.
For example:
48700 48900 48999 49020 49180 49340 ...
Is there some short-hand way of writing the loop?
Or do I just have to painstakingly list all of them?

Answer 1

The answer is it depends.
If these are part of variable names, you can do something like this:
clear
set obs 5
foreach var in 48700 48900 48999 49020 49180 49340 {
generate var`var' = runiform()
}
ds
var48700 var48900 var48999 var49020 var49180 var49340
ds var48*
var48700 var48900 var48999
local names `r(varlist)'
foreach var of local names {
display `var'
}
.41988069
.06420179
.36276805
If these are file names, a macro extended function can be handy:
dir, w
48700.rtf 48999.rtf 49180.rtf
48900.rtf 49020.rtf 49340.rtf
local list : dir . files "*"
display `list'
48700.rtf48900.rtf48999.rtf49020.rtf49180.rtf49340.rtf
local list : dir . files "48*"
display `list'
48700.rtf48900.rtf48999.rtf
foreach fil of local list {
display "`fil'"
}
48700.rtf
48900.rtf
48999.rtf
EDIT:
The above approaches are concerned with how to efficiently get all relevant names in a local macro.
If you already know the names and you merely want a cleaner way to write the loop (or want to re-use the names in several loops), you can simply assign these in a local macro yourself:
local names var48700 var48900 var48999 var49020 var49180 var49340
foreach var of local names {
display `var'
}
.41988069
.06420179
.36276805
.52763051
.16493952
.66403782
The local macro names will automatically expand during run time to include all the specified items.