Accessing an Associative Array 
Accessing an Associative Array
- 
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};   | 
 
 
- 
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. 
 
- 
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 
 |