Newsgroups: comp.lang.perl
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!wuarchive!uunet!convex!usenet
From: Tom Christiansen <tchrist@convex.COM>
Subject: Re: A question on associative arrays
Message-ID: <1991May30.183802.3917@convex.com>
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Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
References: <1991May30.134223.23225@Think.COM>
Distribution: na
Date: Thu, 30 May 1991 18:38:02 GMT
Lines: 23

From the keyboard of sid@think.com (Sid Stuart):
:
:I am writing a Perl application in which I would like to store
:into an associative array only if an entry for that key does
:not exist. The problem is I may come up with duplicate keys and
:I don't want to overwrite the contents of an entry. Is there a
:cheap way to find out if a key is in use? By cheap I mean other
:than using the functions "keys" or "each" to search through all
:the keys of the array.

Barring pathological cases (keys whose values are undef), you
could do this:

    $ary{$key} = $val unless defined $ary{$key};

or perhaps

    $ary{$key} .= $val . ' ';

--tom
--
Tom Christiansen		tchrist@convex.com	convex!tchrist
		"So much mail, so little time."