Question

I have just started with PHP development since last week. I have installed XAMPP on my PC. I just want to know few questions that are:

1. What is the purpose of PEAR folder that is inside the PHP folder?
2. How can I implement polymorphism in PHP?

Answer 1

A PEAR package is distributed as a gzipped tar file. Each archive
consists of source code written in PHP, usually in an object-oriented
style. Many PEAR packages can readily be used by developers as
ordinary third party code via simple include statements in PHP. More
elegantly, the PEAR package manager which comes with PHP by default
may be used to install PEAR packages so that the extra functionality
provided by the package appears as an integrated part of the PHP
installation. Unlike the Comprehensive Perl Archive Network (CPAN)
archives, which PEAR took as its model, PEAR packages do not have
implicit dependencies so that a package’s placement in the PEAR
package tree does not relate to code dependencies. Rather, PEAR
packages must explicitly declare all dependencies on other PEAR
packages.

The PEAR base classes contain code for simulating object-oriented
destructors and consistent error-handling. Packages exist for many
basic PHP functions including authentication, caching, database
access, encryption, configuration, HTML, web services and XML.

http://en.wikipedia.org/wiki/PEAR