The distinction is between assignment and evaluation. If all you want to
do is assign something to a macro, you do not need the = sign and are
often better off without it. The = sign forces Stata to evaluate what it
is given before assigning it to the macro. The most simple example is as
follows:
. local a 2+2
. local b = 2+2
. di "`a'"
2+2
. di "`b'"
4
The first line assigned 2+2 to the local macro a - hereafter it contains
the string "2+2". The second line evaluated 2+2 and assigned the result
to macro b.
The reason why one of your examples worked the same both with and
without the = is that there was nothing to evaluate, so evaluating the
expression did not change the result.
With strings, Stata can assign a long string to a macro, but cannot
evaluate a long string - hence the problems you encountered.
Hope this helps
David
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Jian Zhang
Sent: 26 January 2006 21:29
To: Richard Williams; [email protected];
[email protected]
Subject: Re: st: a question about loop and local marco name
Thanks, Richard! Your explanation is really helpful! also, your guess is
right that I am using Intercooled and Small Stata, which explains why
the local marco command with equal sign does not work since my list has
more
than 80 characters.
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