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 '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
What attribute makes an option from <select> selected?
checked="checked" selected="selected" disabled="disabled"
<select name="a_name">
 <option value="val1">Option 1</option>
 <option value="val2" selected="selected">Option 2</option>
</select>
What CSS value allows to create color gradients for background?
contain repeat-x linear-gradient
#id {
  background: linear-gradient(top left, #1f1, #fff, #11f);
}
What statement creates an array in JavaScript?
[] {} new Object()
var arr = [1, "CoursesWeb.net", "MarPlo.net"];
alert(arr[2]);
Indicate the PHP function used to redirect to other page.
function() header() switch()
header("Location: http://coursesweb.net/");
exit;
PHP Predefined Constants

Last accessed pages

  1. Add and Remove HTML elements and Content with jQuery (30447)
  2. querySelector and querySelectorAll (27242)
  3. Making DIV Contents Scroll Horizontally, with multiple Div`s inside (58770)
  4. Ajax-PHP Rating Stars Script (16246)
  5. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (128412)

Popular pages this month

  1. Courses Web: PHP-MySQL JavaScript Node.js Ajax HTML CSS (72)
  2. PHP Unzipper - Extract Zip, Rar Archives (64)
  3. SHA256 Encrypt hash in JavaScript (38)
  4. Read Excel file data in PHP - PhpExcelReader (32)
  5. SHA1 Encrypt data in JavaScript (29)