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<?php $users = [ ['accounts' => [1, 2]], ['accounts' => [3, 4]], ]; $userAccounts = array_column($users, 'accounts'); $allAccounts = array_merge(...$userAccounts); var_dump($allAccounts);
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array(4) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) }
Output for 5.5.0 - 5.5.38
Parse error: syntax error, unexpected '.' in /in/NmATQ on line 9
Process exited with code 255.
Output for 5.4.0 - 5.4.45
Parse error: syntax error, unexpected '.', expecting ')' in /in/NmATQ on line 9
Process exited with code 255.
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/NmATQ on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.3.11, 4.4.0 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected '[' in /in/NmATQ on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/NmATQ on line 3
Process exited with code 255.

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