eXtropia: the open web technology company
Technology | Support | Tutorials | Development | About Us | Users | Contact Us
Resources
 ::   Tutorials
 ::   Presentations
Perl & CGI tutorials
 ::   Intro to Perl/CGI and HTML Forms
 ::   Intro to Windows Perl
 ::   Intro to Perl 5
 ::   Intro to Perl
 ::   Intro to Perl Taint mode
 ::   Sherlock Holmes and the Case of the Broken CGI Script
 ::   Writing COM Components in Perl

Java tutorials
 ::   Intro to Java
 ::   Cross Browser Java

Misc technical tutorials
 ::   Intro to The Web Application Development Environment
 ::   Introduction to XML
 ::   Intro to Web Design
 ::   Intro to Web Security
 ::   Databases for Web Developers
 ::   UNIX for Web Developers
 ::   Intro to Adobe Photoshop
 ::   Web Programming 101
 ::   Introduction to Microsoft DNA

Misc non-technical tutorials
 ::   Misc Technopreneurship Docs
 ::   What is a Webmaster?
 ::   What is the open source business model?
 ::   Technical writing
 ::   Small and mid-sized businesses on the Web

Offsite tutorials
 ::   ISAPI Perl Primer
 ::   Serving up web server basics
 ::   Introduction to Java (Parts 1 and 2) in Slovak

 

introduction to web programming
Manipulating substrings with the substr function  
Sometimes, you want to work with just part of a string that has been assigned. The substr function follows the syntax:

    $substring = substr([string you want to extract
    from], [beginning point of extraction], [length
    of the extracted value]);

For instance, to assign "Sol" to the scalar variable $last_name you would use the following code:

    $name = "Selena Sol";
    $last_name = substr ($name, 7, 3);

The substr function takes the scalar variable $name, and extracts three characters beginning with the seventh.

WARNING: as in array indexing, the substr function counts from zero, not from one. Thus, in the string "Gunther", the letter "t" is actually referenced as "3" not "4". Also note that the final number (length of extracted value) is not necessary when you want to grab everything "after" the beginning character. Thus, the following code will do just what the previous did since we are extracting the entire end of the variable $name:

$last_name = substr ($name, 7);

Previous | Next | Table of Contents