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Re: st: passing indefinite no of arguments


From   Maarten Buis <maartenlbuis@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: passing indefinite no of arguments
Date   Fri, 30 Mar 2012 21:52:01 +0200

On Fri, Mar 30, 2012 at 8:43 PM, tashi lama wrote:
> So, say I have a do file which will add the arguments and display
>
> *sum
>
> args a b c d
>
> di `a' +`b'+`c'+`d'
>
> This one is easy since I could pass 4 arguments a, b, c and d and my do file will sum them. What if I don't know the no of arguments I am passing? I could have passed 2, 3, 5 or even 1 and find their sum.

Here is a quick solution. The logic is that within a program a number
of locals are created. The local `0' contains all arguments, and the
local `1' contains the first argument, `2' the second, etc. This is
not very stable, e.g. when you call -tokenize- the locals `1', `2'
etc. will be replaced, but in a small program like the one below it is
an easy enough solution.

*---------- begin example ------------
program drop _all
program define sumargs
        // count the number of arguments
	local k : word count `0'

        // add them
	tempname sum
	scalar `sum' = 0
	forvalues i = 1/`k' {
		scalar `sum' = `sum' + ``i''
	}

       // display the result
	di `sum'
end

sumargs 2 3 7
sumargs 4
sumargs 2 3 4 5 6 7 8
*---------- end example -------------





-- 
--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany


http://www.maartenbuis.nl
--------------------------
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