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<?php var_dump(class_exists("TestClass")); //false class TestClass implements JsonSerializable { function __construct() { var_dump(__METHOD__); } public function jsonSerialize() { return null; } } var_dump(class_exists("TestClass")); //true
Output for 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
bool(false) Deprecated: Return type of TestClass::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /in/gcfMs on line 9 bool(true)
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.35, 5.6.0 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30
bool(false) bool(true)
Output for 5.2.3 - 5.2.17, 5.3.0 - 5.3.29
bool(false) Fatal error: Interface 'JsonSerializable' not found in /in/gcfMs on line 3
Process exited with code 255.
Output for 5.0.5, 5.1.1 - 5.1.6, 5.2.0 - 5.2.2
bool(false) <br /> <b>Fatal error</b>: Interface 'JsonSerializable' not found in <b>/in/gcfMs</b> on line <b>3</b><br />
Process exited with code 255.
Output for 5.1.0
<br /> <b>Fatal error</b>: fatal flex scanner internal error--end of buffer missed in <b>/in/gcfMs</b> on line <b>14</b><br />
Process exited with code 255.
Output for 5.0.0 - 5.0.4
bool(false) <br /> <b>Fatal error</b>: Class 'JsonSerializable' not found in <b>/in/gcfMs</b> on line <b>3</b><br />
Process exited with code 255.
Output for 4.4.2 - 4.4.9
<br /> <b>Parse error</b>: syntax error, unexpected T_STRING, expecting '{' in <b>/in/gcfMs</b> on line <b>3</b><br />
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1
<br /> <b>Parse error</b>: parse error, unexpected T_STRING, expecting '{' in <b>/in/gcfMs</b> on line <b>3</b><br />
Process exited with code 255.
Output for 4.3.2 - 4.3.4
<br /> <b>Parse error</b>: parse error, expecting `'{'' in <b>/in/gcfMs</b> on line <b>3</b><br />
Process exited with code 255.

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