constant

(PHP 4 >= 4.0.4, PHP 5)

constant — Returns the value of a constant

Описание

mixed constant ( string $name )

Return the value of the constant indicated by name .

constant() is useful if you need to retrieve the value of a constant, but do not know its name. I.e. it is stored in a variable or returned by a function.

This function works also with class constants.

Список параметров

name: The constant name.

Возвращаемые значения

Returns the value of the constant, or NULL if the constant is not defined.

Примеры

Пример #1 constant() example


<?php

define("MAXSIZE", 100);

echo MAXSIZE;
echo constant("MAXSIZE"); // same thing as the previous line


interface bar {
    const test = 'foobar!';
}

class foo {
    const test = 'foobar!';
}

$const = 'test';

var_dump(constant('bar::'. $const)); // string(7) "foobar!"
var_dump(constant('foo::'. $const)); // string(7) "foobar!"

?>

Смотрите также

define() - Defines a named constant
defined() - Checks whether a given named constant exists
The section on Constants