How to replace multiple variables in one line using Stata

Question

I have some hand corrections to do in a data set and I wanted to do avoid repeating the if condition. For instance, instead of

sysuse auto, clear
replace mpg=21 if make=="AMC Concord"
replace rep78=4 if make=="AMC Concord"
replace mpg=23 if make=="AMC Pacer"
replace rep78=4.5 if make=="AMC Pacer"

the following code would be more parsimonious but it doesn't work

sysuse auto, clear
replace mpg=21 & rep78=4 if make=="AMC Concord"
replace mpg=23 & rep78=5 if make=="AMC Pacer"

Any suggestion would be helpful.

Answer 1

You are right; that code would be more concise. It just is not legal Stata and nothing in the syntax diagram for replace suggests otherwise.

I can imagine some very contrived ways of re-writing the same code in fewer lines, while using if, but none would be, in my view, more attractive or easier to understand.

Looking up the observation number and using in rather than if would also shorten the code, but be less clear and highly fragile to changes in sort order.