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<?php function is_even(int $n): bool { if ($n < 0) { $n = abs($n); } if ($n === 0) { return true; } if ($n === 1) { return false; } return is_even($n - 2); } var_dump(is_even(-4)); die(); for($i = -5; $i <= 12; $i++) { printf('is %d even? %s.%s', $i, is_even($i) ? 'yes': 'no', "\n"); }
Output for 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
bool(true)
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 bool(true)

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