introduction to web programming Using the split and join functions Finally, regular expressions can be used to split a string into separate fields. To do so, we use the "split" function with the format:

    @split_array = split
    (/[pattern_to_split_on]/, [string_to_split]);

For example, CGI applications often use the split function to read the fields of database rows. Consider the following code snippet:

    $database_row = "Selena Sol|213-456-7890|27";
    @database_fields = split (/|/, $database_row);

Now @database_fields will include the elements "Selena Sol", "213-456-7890" and "27". Each of these fields can then be processed separately if need be.

The reverse operation is performed with the "join" function that uses the following format:

    $joined_string = join
    ("[pattern_to_join_on]", [list_to_join]);

Thus, we might recreate the original database row using

    $new_database_row = join ("\|", @database_fields);

Notice that in the above line, the pipe (|) symbol must be escaped with a backslash (\) because the pipe is a special Perl character.

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