uopz_undefine

(PECL uopz 1, PECL uopz 2, PECL uopz 5, PECL uopz 6, PECL uopz 7)

uopz_undefine — Undefine a constant

function uopz_undefine(string $constant): bool

function uopz_undefine(string $class, string $constant): bool

Removes the constant at runtime

Returns true on success or false on failure.

Example #1 uopz_undefine() example

<?php
define("MY", true);

uopz_undefine("MY");

var_dump(defined("MY"));
?>

The above example will output:

bool(false)