PHP

1
PHP

• PHP Personal Home Pages
• PHP is a Hypertext Preprocessor
• For dynamic web pages
• Created in 1994 by Rasmus Lerdorf
• Use in gt 1.5 million web sites, growing
• Server-side scripting language

2
PHP

• PHP is an open-source software
• www.php.net
• Can download for free
• Can interact with database (MySQL for us)
• Can be used with Unix, Linux (for us ), Windows,
  ..

3
PHP

• Need a Web server (Apache for us)
• Need PHP
• All files in .php are handled by the server
  (default)
• PHP scripts are parsed and interpreted on the
  server side of a web application
• Resulting output is sent to web browser for
  display

4
PHP

• PHP is a template
• PHP code for server scripting HTML with embedded
  PHP code in it
• PHP code is embedded using start and end tags
• There are 4 possible sets of tags you can use

5
PHP tags

• 1 - lt?php echo(Hi) ?gt
• 2 - lt? echo(Hi) ?gt
• 3 - ltscript language phpgt
• echo(Hi)
• lt/scriptgt
• 4 - lt echo(ASP style) gt

6
PHP tags

• 1 and 3 are always available
• 2 needs to be enabled (it is for us)
• 4 needs to enable ASP tags (it is not for us)
• Preferred 1 allows XML

7
PHP 1st example

• In file helloworld.php
• lthtmlgtlttitlegtPHP testlt/titlegtltbodygt
• lt?
• echo(Hi)
• ?gt
• lt/bodygtlt/htmlgt

8
PHP echo and print

• PHP has 2 functions for output
• print and echo
• print returns 1 (success) or 0 (failure)
• Also printf and sprintf
• For reserved characters, use \ to escape them
• echo She said \Hi!\

9
PHP comments

• Same as Java, C (and Perl)
• // single line comment
• / multi
• line
• comment /
• a Perl style comment