1. Post-Module PHP Forms BTM 395: Internet Programming

2. Cookies Cookie is a name-value pair stored on the user’s (client) computer –Track preferences and other information Each server’s cookies stored as a text file on client computer –Stored securely so that it is difficult for other server-side applications to access another’s cookies –But don’t store sensitive information (e.g. credit card number) without encryption Security risk if someone has physical access to the user’s computer Write or change cookies: –setcookie( $name, $value ); various optional options (e.g. expiration date) Read cookies –Use the $_COOKIE['name'] environment variable

3. Sessions A session is a built-in way of tracking a user across multiple pages Implemented using cookies Thus, requires cookies to be enabled on client side

4. PHP string quoting ' (single quote): for literal strings with minimal text expansion (\\ and \' only) " (double quote): for flexible strings with expansion of variables and many codes (e.g. \n and \t) Heredoc: for lengthy strings with complex plain-text format (see http://codepad.org/pzHHK3wH)http://codepad.org/pzHHK3wH –Begins with <<<ANY_DELIMITER –Ends with ANY_DELIMITER; as the only contents of closing line –Expands variables similarly to " –Nowdoc format works like single quote equivalent of heredoc Official reference: http://php.net/manual/en/language.types.string.php http://php.net/manual/en/language.types.string.php

5. Array indexing ALL arrays in PHP are associative arrays Numeric indices are automatically generated, but the arrays are still fully associative Arrays can have both flexible associative keys and auto-generated numeric keys Official reference: http://www.php.net/manual/en/language.types.array.php http://www.php.net/manual/en/language.types.array.php

6. Customized array sorting PHP has many built in array sort functions, for sorting by value, by key, and backwards JavaScript only has one very limited built-in sort: lexicographic (strict alphabetic) sort Both have custom sort functions that work similarly –JavaScript: myArray.sort(function(a,b){…});JavaScript –PHP:usort($myArray,customSortFunction); customSortFunction(a,b){…};PHP –These can sort any kind of array anyway you like, including multidimensional arrays

7. Other PHP tips Equality and assignment = vs == vs === The ternary (conditional) operator ? : –$myVar = $testCondition ? $valueIfTrue : $valueIfFalse; –Ternary operator exerciseTernary operator exercise Stop an infinite loop in PHP –Click the stop or cancel button on your browser to stop the page loading –Or just wait 30 seconds or so for a server timeout

8. Sources Heredoc example: http://www.tuxradar.com/practicalphp/2/6/3 http://www.tuxradar.com/practicalphp/2/6/3