Misc. Funzioni
PHP Manual

constant

(PHP 4 >= 4.0.4, PHP 5)

constantReturns the value of a constant

Descrizione

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.

Elenco dei parametri

name

The constant name.

Valori restituiti

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

Errori/Eccezioni

An E_WARNING level error is generated if the constant is not defined.

Esempi

Example #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!"

?>

Vedere anche:


Misc. Funzioni
PHP Manual