Database Journal
MS SQL Oracle DB2 Access MySQL PostgreSQL Sybase PHP SQL Etc SQL Scripts & Samples Links Database Forum

» Database Journal Home
» Database Articles
» Database Tutorials
MS Access
Database Tools
SQL Scripts & Samples
» Database Forum
» Slideshows
» Sitemap
Free Newsletters:
News Via RSS Feed

follow us on Twitter
Database Journal |DBA Support |SQLCourse |SQLCourse2

Featured Database Articles

Database News

Posted Jan 29, 2007

The Building Blocks: Data Types, Literals, Variables, and Constants - Part 3

By Staff

[From WebReference]

Some real-world constants, such as pi, the speed of light, the number of inches in a foot, and the value of midnight, are values that don't change. PHP not only provides its own predefined constants but lets you create your own. Using constants makes it easy to write and maintain your programs.

What Is a Constant?

Unlike variables, a constant is a value that, once set, cannot be changed or unset during the execution of your script. An example of a constant is the value of pi or the version of PHP you are using. Constants are very useful because they are visible throughout a program (global in scope) and their values don't change; for example, a constant might be defined for the document root of your server, the name of your site, or the title, author, and copyright year of this book. Once defined, those values are fixed.

The article continues at

Database News Archives

Comment and Contribute


(Maximum characters: 1200). You have characters left.



Latest Forum Threads
Database News Forum
Topic By Replies Updated
Efficient SQL Server Indexing by Design lcole 0 April 30th, 12:38 PM
Mine Oracle Database, SQL Server and Other Databases with Monarch Data Pump Pro V10.5 lcole 0 April 30th, 12:37 PM
Oracle Database and Oracle Fusion Middleware for Private Social Network Application lcole 0 April 30th, 12:31 PM
Oracle Database Maintains a Stronghold in the DBMS Market lcole 0 April 30th, 12:30 PM