(PHP 4 >= 4.0.4, PHP 5, PHP 7)
constant — Returns the value of a constant
constant ( string $name ) : mixed
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.
name
The constant name.
Returns the value of the constant, or null if the constant is not defined.
An E_WARNING level error is generated if the constant is not defined.
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!"
?>
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https://www.php.net/manual/en/function.constant.php