3v4l.org

run code in 300+ PHP versions simultaneously
<?php interface I { public function example(); } class A implements I { public function example(): int { } // compatible with I::example } class B extends A { public function example(): string { } // compatible with I::example }
Output for 8.5.0 - 8.5.3
Fatal error: Declaration of B::example(): string must be compatible with A::example(): int in /in/Jik7I on line 10 Stack trace: #0 {main}
Process exited with code 255.
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18
Fatal error: Declaration of B::example(): string must be compatible with A::example(): int in /in/Jik7I on line 10
Process exited with code 255.
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33
Fatal error: Declaration of B::example(): string must be compatible with A::example(): int in /in/Jik7I on line 9
Process exited with code 255.
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33
Output for 5.6.0 - 5.6.40
Parse error: syntax error, unexpected ':', expecting ';' or '{' in /in/Jik7I on line 7
Process exited with code 255.
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