3v4l.org

run code in 300+ PHP versions simultaneously
<?php $numbers = [4, 3, 4, 3, 1, 2, 1]; var_export( array_keys( array_intersect( array_count_values($numbers), [1] ) ) ); echo "\n---\n"; var_export( array_keys( array_filter( array_count_values($numbers), function($count) { return $count === 1; } ) ) ); echo "\n---\n"; // PHP7.4+ var_export( array_keys( array_filter( array_count_values($numbers), fn($count) => $count === 1 ) ) );
Output for 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.4, 8.3.6 - 8.3.7
array ( 0 => 2, ) --- array ( 0 => 2, ) --- array ( 0 => 2, )
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 array ( 0 => 2, ) --- array ( 0 => 2, ) --- array ( 0 => 2, )
Output for 7.3.0 - 7.3.33
Parse error: syntax error, unexpected '=>' (T_DOUBLE_ARROW), expecting ')' in /in/ULAkV on line 30
Process exited with code 255.
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.34
Parse error: syntax error, unexpected '=>' (T_DOUBLE_ARROW), expecting ',' or ')' in /in/ULAkV on line 30
Process exited with code 255.
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