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 'https://coursesweb.net/'. PHP_EOL .'Next line';
__LINE__ - The current line number of the file.
<?php
// 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

HTML
CSS
JavaScript
PHP-MySQL
Which HTML5 tag is indicated to be used as container for menu with navigation links in Web site?
<section> <nav> <article>
<nav><ul>
 <li><a href="http://coursesweb.net/css/" title="CSS Course">CSS Course</a></li>
 <li><a href="http://www.marplo.net/jocuri/" title="Flash Games">Flash Games</a></li>
</ul></nav>
Which CSS property shifts an item horizontally to the left or right of where it was?
text-align clear float
.some_class {
  width: 30%;
  float: left;
}
Click on the Math object method which returns x, rounded downwards to the nearest integer.
Math.ceil(x) Math.abs(x) Math.floor(x)
var num = 12.34567;
num = Math.floor(num);
alert(num);       // 12
Indicate the PHP function which returns the number of characters in string.
mb_strlen() count() stristr()
$str = "string with utf-8 chars åèö";
$nrchr = mb_strlen($str);
echo $nrchr;        // 30
PHP Predefined Constants

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