Php-mysql Course

Useful PHP Predefined Constants defined by the PHP core.

PHP_VERSION - Contains a string with the current PHP version.
echo PHP_VERSION; // 5.5.3
PHP_MAXPATHLEN - The maximum length of filenames (including path) supported by this build of PHP.
echo PHP_MAXPATHLEN; // 260
PHP_OS - Contains a string that can be used to detect the operatig system PHP is running on. Some posible values:
CYGWIN_NT-5.1, Darwin (for Mac Os X), FreeBSD, HP-UX, IRIX64, Linux, NetBSD, OpenBSD, SunOS, Unix, WIN32, WINNT (for Windows NT), Windows, CYGWIN_NT-5.1, IRIX64, SunOS, HP-UX, OpenBSD.
echo PHP_OS; // WINNT
PHP_EOL - The correct 'End Of Line' symbol for the platform on which PHP is running on. Useful to add new lines in strings.
echo ''. PHP_EOL .'Next line';
__LINE__ - The current line number of the file.
// test
echo __LINE__;       // 3
__FILE__ - The full path and filename of the current php file. If used inside an include, the name of the included file is returned.
echo __FILE__; // D:\server\www\file.php
__DIR__ - The directory of the current php file. If used inside an include, the directory of the included file is returned. This is equivalent to: dirname(__FILE__). Not have a trailing slash unless it is the root directory.
echo __DIR__; // D:\server\www
__FUNCTION__ - The function name in which this constant is accessed.
function someName() {
  echo __FUNCTION__;
someName();      // someName
__CLASS__ - Returns the class name as it was declared (case-sensitive).
class someClass {
  public function className() {
    return __CLASS__;

$obj = new someClass();
echo $obj->className();      // someClass
__METHOD__ - Returns the class method name as it was declared, including the class name (case-sensitive).
class someClass {
  public function someMethod() {
    return __METHOD__;

$obj = new someClass();
echo $obj->someMethod();      // someClass::someMethod

Daily Test with Code Example

Which tag can be used to create input text field in web page?
<form> <input> <div>
<input type="text" name="a_name" value="val" />
Which CSS property displays the text in a small-caps font?
display font-variant font-style
h3 {
  font-variant: small-caps;
What instruction displays a notice box with a message inside it, in JavaScript?
for() Date() alert()
var msg = "Visit";
Indicate the PHP code used to get the users IP.
echo $ip;
PHP Predefined Constants

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