02 — PHP Magic Constants
__LINE__
This returns the current line number of the file.
//Example 1: __LINE__
//For this example, we'll assume that this
//statement is on the fifth line of a file.
echo(__LINE__);
//This statement returns "5".
__FILE__
This returns the full path and filename of the current file.
//Example 2: __FILE__
//For this example, we'll assume that this code is
//somewhere inside of a file called "example.php" and that
//the file "example.php" is in the root directory "httpdocs".
echo(__FILE__);
//This statement returns "httpdocs/example.php".
__DIR__
This returns the directory of the current file.
//Example 3: __DIR__
//For this example, we'll assume that this code is
//somewhere inside of a file called "example.php" and that
//the file "example.php" is in the root directory "httpdocs".
echo(__DIR__);
//This statement returns "httpdocs/".
__FUNCTION__
This returns the name of the current function. If the current function is an anonymous function, {closure} is returned instead.
//Example 4: __FUNCTION__
function exampleFunction()
{
echo(__FUNCTION__);
//This statement returns "exampleFunction".
}