How do you set up 'syntax' code to be able to reference specific input variables later in a program?

[Matt Warkentin]

Long time Stata user, relatively new to writing Stata programs.

I'm trying to write a new program (something trivial for the purposes of practice) and I am having difficulty getting off the ground.

When setting up the 'syntax' line of the program, I want the program to accept two numeric variables only, that will be used for other tasks through the program...

For example:

program define example
syntax varlist(min=2 max=2 numeric) [if] [in] , [...]

This will meet my first requirement of exactly two variables needed for program, however, I want to be able to refer to the variables specifically moving forward with the program, treating one variable as 'y-variable' and one as the 'x-variable'. I imagine there is a simple way to do this but I can't figure it out.

In other words, when a varlist is provided with a command, how am I able to reference the first or second variable specifically when doing other tasks?

Any help is appreciated. Thanks.

[Clyde Schechter]

local var1: word 1 of `varlist'
local var2: word 2 of `varlist'

// THEREAFTER REFERENCE THESE AS `var1' AND `var2'

[Nick Cox]

Clyde is right but a nice alternative is

tokenize "`varlist'" 
args y x somethingelse president2017 whatever

Notice how we can use two lines even though (in this example) we are expecting five variables.

[Matt Warkentin]

Thanks to both of you for the responses! Both worked...now on to troubleshooting other programming issues.

[Richard Williams]

My favorite:

gettoken y x: varlist

y gets the yvar, x gets all the x vars.