Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: RE: strange foreach loop result

From   Matthew Watt <>
To   "" <>
Subject   st: RE: strange foreach loop result
Date   Wed, 15 Dec 2010 11:53:02 -0500

Do you get the same results if you use an "if/else if" structure instead of a pure if structure?  As you have it now, each of your loop's tests is independent of the previous tests, meaning that even if `var' == slope, you test to see if `var' also equals lower, upper, and ed50.  The result of this is that if `var' equals both slope and ed50, you will assign a value of 4 to slope.  If you use an if/else structure, the else clause will only be tested if the "if" clause is false.

Of course, you may end up with ed50 having a value of 1 if ed50 and slope are equal, should you use if/else.


-----Original Message-----
From: [] On Behalf Of Airey, David C
Sent: Wednesday, December 15, 2010 11:40 AM
Subject: st: strange foreach loop result


I'm getting a really strange foreach loop result I don't understand.

In the first code snippet on fictitious data, I get what I want. In the second code snippit on the real data I get a strange result for when the condition:

if `var' == slope local myvar 1

is evaluated when `var' is slope. It produces the result myvar==4, when it should return myvar==1.

Anyone have a clue where my error is?

set obs 10
gen a = 1
gen b = 2
gen c = 3
gen d = 4
foreach var of varlist a b c d {
        if `var' == a local myvar 1
        if `var' == b local myvar 2
        if `var' == c local myvar 3
        if `var' == d local myvar 4
        display "`var'", "`myvar'"


a 1
b 2
c 3
d 4

use result_pilot.dta, clear
keep slope lower upper ed50
foreach var of varlist slope lower upper ed50 {
        if `var' == slope local myvar 1
        if `var' == lower local myvar 2
        if `var' == upper local myvar 3
        if `var' == ed50 local myvar 4
        display "`var'", "`myvar'"


slope 4 <--weird, should be slope 1
lower 2
upper 3
ed50 4

*   For searches and help try:

This email message and any attachments are for the sole use of the intended recipients and may contain proprietary and/or confidential information which may be privileged or otherwise protected from disclosure. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not an intended recipient, please contact the sender by reply email and destroy the original message and any copies of the message as well as any attachments to the original message.

*   For searches and help try:

© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index