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<?php $alternatives = array( 'foo:bar' => 1, 'foo:bar1' => 1, 'foo1:bar' => -4, ); asort($alternatives); print_r($alternatives); print_r(array_keys($alternatives));
Output for 7.0.0 - 7.0.20, 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 - 8.2.17, 8.3.0 - 8.3.4
Array ( [foo1:bar] => -4 [foo:bar] => 1 [foo:bar1] => 1 ) Array ( [0] => foo1:bar [1] => foo:bar [2] => foo:bar1 )
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28
Array ( [foo1:bar] => -4 [foo:bar1] => 1 [foo:bar] => 1 ) Array ( [0] => foo1:bar [1] => foo:bar1 [2] => foo:bar )

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225.16 ms | 402 KiB | 268 Q