cvs: phpdoc /en/language functions.xml

philip Sat May 17 11:54:41 2003 EDT Modified files: /phpdoc/en/language functions.xml Log: Added a new section: functions.internal It explains PHP's built-in functions. Index: phpdoc/en/language/functions.xml diff -u phpdoc/en/language/functions.xml:1.36 phpdoc/en/language/functions.xml:1.37 --- phpdoc/en/language/functions.xml:1.36 Sat May 17 10:29:40 2003 +++ phpdoc/en/language/functions.xml Sat May 17 11:54:41 2003 @@ -1,5 +1,5 @@ <?xml version="1.0" encoding="iso-8859-1"?> -<!-- $Revision: 1.36 $ --> +<!-- $Revision: 1.37 $ --> <chapter id="functions"> <title>Functions</title> @@ -504,6 +504,51 @@ variable variables</link> and <function>function_exists</function>. </para> </sect1> + + <sect1 id="functions.internal"> + <title>Internal (built-in) functions</title> + + <para> + PHP comes standard with many functions and constructs. There are also + functions that require specific PHP extensions compiled in otherwise + you'll get fatal "undefined function" errors. For example, to use + <link linkend="ref.image">image</link> functions such as + <function>imagecreatetruecolor</function>, you'll need your PHP compiled + with GD support. Or, to use <function>mysql_connect</function> you'll + need your PHP compiled in with <link linkend="ref.mysql">MySQL</link> + support. There are many core functions that are included in every + version of PHP like the <link linkend="ref.strings">string</link> and + <link linkend="ref.variables">variable</link> functions. A call + to <function>phpinfo</function> or + <function>get_loaded_extensions</function> will show you which + extensions are loaded into your PHP. Also note that many extensions are + enabled by default and that the PHP manual is split up by extension. + See the <link linkend="configuration">configuration</link>, + <link linkend="installation">installation</link>, and individual + extension chapters, for information on how to setup your PHP. + </para> + <para> + Reading and understanding a functions prototype is explained within the + manual section titled + <link linkend="about.prototypes">how to read a function definition</link>. + It's important to realize what a function returns or if a function works + directly on a passed in value. For example, + <function>str_replace</function> will return the modified string while + <function>usort</function> works on the actual passed in variable + itself. Each manual page also has specific information for each + function like information on function parameters, behavior changes, + return values for both success and failure, and availability information. + Knowing these important (yet often subtle) differences is crucial for + writing correct PHP code. + </para> + <para> + See also <function>function_exists</function>, + <link linkend="funcref">the function reference</link>, + <function>get_extension_funcs</function>, and + <function>dl</function>. + </para> + </sect1> + </chapter> <!-- Keep this comment at the end of the file