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".

• 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
• Perl Resources
• Libraries for CGI Form Handling in Perl

Perl Associative Arrays
Table of Contents
Using the keys and values functions