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From: allbery@NCoast.ORG (Brandon S. Allbery KB8JRR)
Newsgroups: comp.lang.perl
Subject: Re: apply in Perl?
Message-ID: <1991Feb17.172151.20509@NCoast.ORG>
Date: 17 Feb 91 17:21:51 GMT
References: <VICTOR.91Feb13112228@irt.watson.ibm.com>
Reply-To: allbery@ncoast.ORG (Brandon S. Allbery KB8JRR)
Followup-To: comp.lang.perl
Distribution: comp
Organization: North Coast Public Access Un*x (ncoast)
Lines: 35

As quoted from <VICTOR.91Feb13112228@irt.watson.ibm.com> by victor@arnor.uucp:
+---------------
| foreach (1..$limit) {$a[$_ -1] = "foobar.$f";}
| 
| Of course I'd like to produce this array without giving it a name.  It
| seems that grep("foobar.$_",(1..$limit)) actually evaluates these
| things, and then throws them away.  Is there some hack to use grep (or
| maybe something else) to actually produce the array?
+---------------

It's not clear to me what you're trying to accomplish.  Maybe

	grep(push(@a, "foobar.$_"), (1 .. $limit));

which creates the same array as your foreach example.  Or, more concisely,

	@a = grep("foobar.$_", (1 .. $limit));

(Grep returns all "true" values, meaning anything that is not either numeric 0
or an empty string, generated by the expression.)

If you want to built it and act on it immediately, just use the value of the
grep:

	foreach (grep("foobar.$_", (1 .. $limit)))
	{
	    # this executes for each generated value, with the value in $_
	}

++Brandon
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