SubReturnValue.pl - Example on Return Values

Perl Tutorials - Herong's Tutorial Examples

∟SubReturnValue.pl - Example on Return Values

This section provides a tutorial example on how a list value can be returned from a subroutine to the caller using the return statement.

As mentioned in the previous section, all return values are passed back to the caller as a single list of scalars. If a list (array or hash) is used as a return value, it will be exploded into multiple return values with its elements.

Here is a tutorial example on how to return a list value to the caller:

#- SubReturnValue.pl
#- Copyright (c) HerongYang.com. All Rights Reserved.
#
   $a = 'hello';
   @a = ('mon','tue','wed','thu','fri');
   print &subReturnValue($a), "\n";
   print $a, "\n";
   print join(',',&subReturnValue(@a)), "\n";
   print join(',',@a), "\n";
   exit;
sub subReturnValue {
   my @l = @_;
   foreach (@l) {
      tr/a-z/A-Z/;
   }
   return @l;
}

Here is the output of the tutorial script:

HELLO
hello
MON,TUE,WED,THU,FRI
mon,tue,wed,thu,fri

The output clearly shows you that an array can be easily returned to the caller.

Table of Contents

About This Book

Perl on Linux Systems

ActivePerl on Windows Systems

Data Types: Values and Variables

Expressions, Operations and Simple Statements

►User Defined Subroutines

Declaring and Calling Subroutines

SubParamList.pl - Example on Parameter List

SubParamAlias.pl - Example on Parameters as Alias

►SubReturnValue.pl - Example on Return Values

SubCalling.pl - Example on Calling Formats

Perl Built-in Debugger

Name Spaces and Perl Module Files

Symbolic (or Soft) References

Hard References - Addresses of Memory Objects

Objects (or References) and Classes (or Packages)

Typeglob and Importing Identifiers from Other Packages

String Built-in Functions and Performance

File Handles and Data Input/Output

Open Files in Binary Mode

Open Directories and Read File Names

File System Functions and Operations

Image and Picture Processing

Using DBM Database Files

Using MySQL Database Server

Socket Communication Over the Internet

XML::Simple Module - XML Parser and Generator

XML Communication Model

SOAP::Lite - SOAP Server-Client Communication Module

Perl Programs as IIS Server CGI Scripts

CGI (Common Gateway Interface)

XML-RPC - Remote Procedure Call with XML and HTTP

RPC::XML - Perl Implementation of XML-RPC

Integrating Perl with Apache Web Server

CGI.pm Module for Building Web Pages

LWP::UserAgent and Web Site Testing

Converting Perl Script to Executable Binary

Managing Perl Engine and Modules on macOS

Archived Tutorials

References

Full Version in PDF/EPUB