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run code in 300+ PHP versions simultaneously
<?php $ignore = array('44'=>'GLOBALS', '_FILES', '_COOKIE', '_POST', '_GET', '_SERVER', '_ENV', 'ignore'); var_dump($ignore); $i2=array_flip($ignore); var_dump($i2);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 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 - 8.1.27, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(8) { [44]=> string(7) "GLOBALS" [45]=> string(6) "_FILES" [46]=> string(7) "_COOKIE" [47]=> string(5) "_POST" [48]=> string(4) "_GET" [49]=> string(7) "_SERVER" [50]=> string(4) "_ENV" [51]=> string(6) "ignore" } array(8) { ["GLOBALS"]=> int(44) ["_FILES"]=> int(45) ["_COOKIE"]=> int(46) ["_POST"]=> int(47) ["_GET"]=> int(48) ["_SERVER"]=> int(49) ["_ENV"]=> int(50) ["ignore"]=> int(51) }

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