Contents (index)

• PHP Samples
• : See Also
• : PHP comments
• : PHP variables
• : PHP functions
• : PHP Arrays
• : Getting data from an HTML form
• : PHP classes
• : PHP constants
• : PHP Sample Code Quick Reference
• Index of defined terms etc.

PHP Samples

This page was created by Paul Conrad as part of his Graduate Independent Study (CSCI695) of the syntax and semantics of the PHP language.

This page contains all of the code samples for PHP.

See Also

For a quick, concise reference to terms used through out this page, see [ ./php.glossary.html ] which contains meta-linguistic terms, lexemes, and keyword definitions based on the C++ glossary found at [ c++.glossary.html ] with the appropriate adaptations to PHP.

PHP comments

 <?php

      /* Initialize some variables using C style comments

         $a - contains a-coefficient

         $b - contains b-coefficient

         $x - value we are evaluating

         $y - result from evaluating equation */

      $a = 1; $b = 2; $x = 1;

      $y = $a * $x + $b;

      if ( $y < 5 )                // C++ style comment, check if y<5

      {

              # Shell style comment, display something when y<5

              echo "Guess what?  y is less than 5!";

      }

 ?>

To see this script in action, visit [ ./php_samples/comment_sample.php ] .

PHP variables

 <?php

      $count = 0;     // Set count equal to 0

      $_xval = 5;

      $_yval = 1.0;

      $some_string = "Hello There!";

      $will i work=6; // This does not work!!!

      $3blindmice=3;  // Same here, does not work

 ?>

To see this script in action, visit [ ./php_samples/variable_sample.php ] (script does not include the two lines that will fail).

PHP functions

 <?php

      function m_x_plus_b($m, $x, $b) {

            return $m*$x+$b;

      }

      $slope=1.5;

      $x=2;

      $b=3;

      echo "y = ".m_x_plus_b($slope,$x,$b)."<br>";

 ?>

To see this script in action, visit [ ./php_samples/function_sample1.php ] .

The following script is an example of case-insensitivity with function names in PHP. To see this script in action, visit [ ./php_samples/function_sample2.php ] .

 <?php

      // This is a sample script from Paul Conrad's Independent Study

      // This script will call the function named foo showing case insensitivity.

      function foo($my_string) {

              echo "$"."my_string = $my_string<br>";

      }

      foo("foo is foo");

      Foo("Foo is foo");

      FoO("FoO is foo");

      FOO("FOO is foo");

 ?>

The two following sample scripts show two different ways of using the same anonymous function.

 <?php

        $lambda=create_function('$a,$b','return(strlen($a)-strlen($b));');

        $array=array('really long string here, boy','middling length','larger');

        usort($array,$lambda);

        print_r($array);

 ?>

To see this script in action, visit [ ./php_samples/anonymous_function.php ] .

 <?php

        $array=array('really long string here, boy','middling length','larger');

        usort($array,create_function('$a,$b','return(strlen($a)-strlen($b));'));

        print_r($array);

 ?>

To see this script in action, visit [ ./php_samples/anonymous_function2.php ]

PHP Arrays

Arrays are associative and can use strings(in quotes) or integers.

PHP_Arrays

Getting data from an HTML form

Data sent from an HTML form is presented to a PHP script as an array. It may be the array $_GET or the array of $_POST.

Before you access an element in one of these arrays you need to check to see it exists. Recall that any PHP script can be called by typing inits URL... and so any or no data can be delivered. The following function handles this.

 function get($key)

 {

  if (array_key_exists($key,$_POST))

          return $_POST[$key];

  else

           return "";

 }

 $SUBJECT=get('subject');

 $FROM=get('from');

 $MESSAGE=get('message');

 $SIGNED=get('signed');

PHP classes

 <?php

      class Programmer {

           // Class Properties

           var $name;         // Programmer's name

           var $experience;   // How long has been programming

           var $lang;         // Favorite Language

           var $education;    // Highest degree earned

           // Class Constructor - function same name as the class

           function Programmer($name, $experience, $lang, $education) {

                $this->name=$name;

                $this->experience=$experience;

                $this->lang=$lang;

                $this->education=$education;

           }

           // Getter/Setter functions for all properties in the class

           function get_name() {

                return $this->name;

           }

           function set_name($newname) {

                $this->name = $newname;

           }

           function get_experience() {

                return $this->experience;

           }

           function set_experience($newexperience) {

                $this->experience = $newexperience;

           }

           function get_lang() {

                return $this->lang;

           }

           function set_lang($newlang) {

                $this->lang = $newlang;

           }

           function get_education() {

                return $this->education;

           }

           function set_education($neweducation) {

                $this->education = $neweducation;

           }

           // Utility data dump function

           function output() {

                echo "Programmer Name: ".$this->name."<br>";

                echo $this->name." has ".$this->experience." years of programming experience.<br>";

                echo $this->lang." is ".$this->name."'s favorite programming language.<br>";

                echo $this->name." holds the degree: ".$this->education."<br><br>";

           }

      }

      // Instantiating a programmer

      $paul = new Programmer('Paul Conrad',12,'C++','Bachelor of Science in Computer Science');

      $paul->output();

      // Oops, Paul has programmed alot longer than 12 year, really is 22 years

      $paul->set_experience(22);

      $paul->output();

 ?>

To see this script in action, visit [ ./php_samples/class_sample.php ] .

PHP constants

 <?php

      define('school',"California State University at San Bernardino");

      define('programs',4);

      echo "Our school is ".school."<br>";

      echo "Our school's Computer Science Dept has ".programs." academic programs";

 ?>

To see this script in action, visit [ ./php_samples/constant_sample.php ] .

PHP Sample Code Quick Reference

Example PHP Script Source File Description
[ ./php_samples/anonymous_function.php ]	[ ./php_samples/anonymous_function.txt ]	Sample of anonymous functions at work.
[ ./php_samples/anonymous_function2.php ]	[ ./php_samples/anonymous_function2.txt ]	Another anonymous function sample, no assigned variable, though (YAGNI).
[ ./php_samples/assignment1.php ]	[ ./php_samples/assignment1.txt ]	Sample of assigning values to variables and doing some strange operations.
[ ./php_samples/block.php ]	[ ./php_samples/block.txt ]	Example of block scope and } is not required when ?> tag encountered.
[ ./php_samples/class_extends.php ]	[ ./php_samples/class_extends.txt ]	Sample showing how classes are inherited in PHP.
[ ./php_samples/class_sample.php ]	[ ./php_samples/class_sample.txt ]	Sample class of a class named Programmer.
[ ./php_samples/comment_sample.php ]	[ ./php_samples/comment_sample.txt ]	Sample showing how comments can be done in PHP.
[ ./php_samples/constant_sample.php ]	[ ./php_samples/constant_sample.txt ]	Sample showing how to define constants in PHP.
[ ./php_samples/const_in_class.php ]	[ ./php_samples/const_in_class.txt ]	Experiment to see what the scope of define'd constants are in PHP.
[ ./php_samples/define1.php ]	[ ./php_samples/define1.txt ]	A way to define a constant in PHP. Just displays a 1 - constant is defined.
[ ./php_samples/define2.php ]	[ ./php_samples/define2.txt ]	Another way to define a constant in PHP. Displays the value of the constant.
[ ./php_samples/define3.php ]	[ ./php_samples/define3.txt ]	An experiment in which 'a' contains the constant, and b is 1.

. . . . . . . . . ( end of section PHP Samples) <<Contents | Index>>