Accessing an Associative Array
Accessing an Associative Array
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If we want to extract a value from the associative array, we reference
it with the following syntax:
$variable_equal_to_value =
$ASSOCIATIVE_ARRAY_NAME{'[key]'};
Thus, to pull out the value of the "full_name" key from %CLIENT_ARRAY,
we use the following syntax:
$full_name = $CLIENT_ARRAY{'full_name'}
The variable $full_name would then be equal to "Selena Sol". Think of it
as using a "key" to unlock a "value".
When accessing an associative array using a scalar
variable as a key, you should not surround the key with single quotes
because the scalar variable will not be interpolated. For example, the
following syntax generates the value for the age key
$key_name = "age";
$age = $CLIENT_ARRAY{$key_name}; |
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Accessing an associative array is one of the most basic CGI
functions and is at the heart of the ReadParse routine in cgi-lib.pl
that creates an associative array from the incoming form data. We will
talk more about ReadParse later today.
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By accessing this associative array (usually referred to as %in or %form_data),
your CGI script will be able to determine what it is that the client has
asked of it since HTML form variables are formed in terms of administratively-defined
NAMES and client-defined VALUES using syntax such as the following:
<INPUT TYPE = "text" NAME = "full_name"
SIZE = "40">
The "key" of the associative array generated by ReadParse will be "full_name"
and the "value" will be whatever the client typed into the text box.
Additional Resources:
Perl
Associative Arrays
Table of Contents
Using
the keys and values functions
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