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run code in 150+ php & hhvm versions
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<?php define("NULL", false); if (true) { echo "TRUE"; } else { echo "FALSE"; }
Output for 4.3.0 - 5.6.28, 7.0.0 - 7.1.0
TRUE
Output for hhvm-3.10.0 - 3.12.0
Notice: Constant NULL already defined in /in/5At6B on line 4 TRUE