ثابت ها در php – تعریف ثابت ها و ثابت های از پیش تعریف شده php – ثابت های جادویی php

//Syntax of define constant in php
define(name, value, case-insensitive);

define('MSN_INTEGER',100);
echo MSN_INTEGER; //it will print 100 in output

define('MSN_INTEGER',100,true);
echo MSN_INTEGER;
echo Msn_InTeger;
echo msn_integer;

//results of all are the same

define("MSN_WELCOME", "Welcome to WPWebmaster site.");

function msnTest() {
    echo MSN_WELCOME;
}
 
msnTest();
//it will print related message in output

PHP_VERSION (string)
//The current PHP version as a string in "major.minor.release[extra]" notation.

PHP_MAJOR_VERSION (integer)
//The current PHP "major" version as an integer (e.g., int(5) from version "5.2.7-extra"). Available since PHP 5.2.7.

PHP_MINOR_VERSION (integer)
//The current PHP "minor" version as an integer (e.g., int(2) from version "5.2.7-extra"). Available since PHP 5.2.7.

PHP_RELEASE_VERSION (integer)
//The current PHP "release" version as an integer (e.g., int(7) from version "5.2.7-extra"). Available since PHP 5.2.7.

PHP_VERSION_ID (integer)
//The current PHP version as an integer, useful for version comparisons (e.g., int(50207) from version "5.2.7-extra"). Available since PHP 5.2.7.

PHP_EXTRA_VERSION (string)
//The current PHP "extra" version as a string (e.g., '-extra' from version "5.2.7-extra"). Often used by distribution vendors to indicate a package version. Available since PHP 5.2.7.

PHP_ZTS (integer)
//Available since PHP 5.2.7.

PHP_DEBUG (integer)
//Available since PHP 5.2.7.

PHP_MAXPATHLEN (integer)
//The maximum length of filenames (including path) supported by this build of PHP. Available since PHP 5.3.0.

PHP_OS (string)
//The operating system PHP was built for.

PHP_OS_FAMILY (string)
//The operating system family PHP was built for. Either of 'Windows', 'BSD', 'Darwin', 'Solaris', 'Linux' or 'Unknown'. Available as of PHP 7.2.0.

PHP_SAPI (string)
//The Server API for this build of PHP. See also php_sapi_name().

PHP_EOL (string)
//The correct 'End Of Line' symbol for this platform. Available since PHP 5.0.2

PHP_INT_MAX (integer)
//The largest integer supported in this build of PHP. Usually int(2147483647) in 32 bit systems and int(9223372036854775807) in 64 bit systems. Available since PHP 5.0.5

PHP_INT_MIN (integer)
//The smallest integer supported in this build of PHP. Usually int(-2147483648) in 32 bit systems and int(-9223372036854775808) in 64 bit systems. Available since PHP 7.0.0. Usually, PHP_INT_MIN === ~PHP_INT_MAX.

PHP_INT_SIZE (integer)
//The size of an integer in bytes in this build of PHP. Available since PHP 5.0.5

PHP_FLOAT_DIG (integer)
//Number of decimal digits that can be rounded into a float and back without precision loss. Available as of PHP 7.2.0.

PHP_FLOAT_EPSILON (float)
//Smallest representable positive number x, so that x + 1.0 != 1.0. Available as of PHP 7.2.0.

PHP_FLOAT_MIN (float)
//Smallest representable floating point number. Available as of PHP 7.2.0.

PHP_FLOAT_MAX (float)
//Largest representable floating point number. Available as of PHP 7.2.0.

DEFAULT_INCLUDE_PATH (string)

PEAR_INSTALL_DIR (string)

PEAR_EXTENSION_DIR (string)

PHP_EXTENSION_DIR (string)

PHP_PREFIX (string)
//The value "--prefix" was set to at configure.

PHP_BINDIR (string)
//Specifies where the binaries were installed into.

PHP_BINARY (string)
//Specifies the PHP binary path during script execution. Available since PHP 5.4.

PHP_MANDIR (string)
//Specifies where the manpages were installed into. Available since PHP 5.3.7.

PHP_LIBDIR (string)

PHP_DATADIR (string)

PHP_SYSCONFDIR (string)

PHP_LOCALSTATEDIR (string)

PHP_CONFIG_FILE_PATH (string)

PHP_CONFIG_FILE_SCAN_DIR (string)

PHP_SHLIB_SUFFIX (string)
//The build-platform's shared library suffix, such as "so" (most Unixes) or "dll" (Windows).

PHP_FD_SETSIZE (string)
//The maximum number of file descriptors for select system calls. Available as of PHP 7.1.0.

E_ERROR (integer)
//Error reporting constant

E_WARNING (integer)
//Error reporting constant

E_PARSE (integer)
//Error reporting constant

E_NOTICE (integer)
//Error reporting constant

E_CORE_ERROR (integer)
//Error reporting constant

E_CORE_WARNING (integer)
//Error reporting constant

E_COMPILE_ERROR (integer)
//Error reporting constant

E_COMPILE_WARNING (integer)
//Error reporting constant

E_USER_ERROR (integer)
//Error reporting constant

E_USER_WARNING (integer)
//Error reporting constant

E_USER_NOTICE (integer)
//Error reporting constant

E_RECOVERABLE_ERROR (integer)
//Error reporting constant. Available since PHP 5.2.0

E_DEPRECATED (integer)
//Error reporting constant. Available since PHP 5.3.0

E_USER_DEPRECATED (integer)
//Error reporting constant. Available since PHP 5.3.0

E_ALL (integer)
//Error reporting constant

E_STRICT (integer)
//Error reporting constant

__COMPILER_HALT_OFFSET__ (integer)
//Available since PHP 5.1.0

TRUE (boolean)

FALSE (boolean)

NULL (null)

echo "Line number " . __LINE__ . "<br>"; // Displays: Line number 1
echo "Line number " . __LINE__ . "<br>"; // Displays: Line number 2
echo "Line number " . __LINE__ . "<br>"; // Displays: Line number 3
echo "Line number " . __LINE__ . "<br>"; // Displays: Line number 4

echo "The full path of this file is: " . __FILE__;
// Displays the absolute path of this file

echo "The directory of this file is: " . __DIR__;
// Displays the directory of this file

function msnFunction(){
    echo  "The function name is - " . __FUNCTION__;
}
msnFunction(); 
// Displays: The function name is: msnFunction

class MsnClass
{
    public function getClassName(){
        return __CLASS__;
    }
}

$sample_object = new MsnClass();

echo $sample_object->getClassName(); 
// Displays: MsnClass

class MsnSample
{
    public function msnMethod(){
        echo __METHOD__;
    }
}

$sample_object = new MsnSample();

$sample_object->msnMethod(); 
// Displays: Sample::msnMethod

namespace MsnNamespace;
class MsnClass
{
    public function getNamespace(){
        return __NAMESPACE__;
    }
}

$sample_object = new MyClass();

echo $sample_object->getNamespace(); 
// Displays: MsnNamespace