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<?php const A = 1; class C { public const D = 1; private const E = 1; } use const A as B; // global constants var_dump(defined('A')); var_dump(defined('\A')); var_dump(defined('\\A')); // good joke var_dump(defined('B')); // false var_dump(defined(A)); // checking the constant value // class constants var_dump(defined('C::D')); var_dump(defined('C::E')); // including visibility
Output for 8.2.31 - 8.2.34, 8.3.0 - 8.3.35, 8.4.1 - 8.4.26, 8.5.0 - 8.5.11
bool(true) bool(true) bool(true) bool(false) bool(false) bool(true) bool(false)

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27.53 ms | 1152 KiB | 7 Q