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<?php $v = Array( 'ccrs_date', Array( 'prelim_title_report_date', Array( 'additional_escrow_deposit_date', Array( 'earnest_money_date', Array( 'acceptance_date', Array( 'contract_date', Array( 'prelim_title_report_date' ) ) ) ) ) ) ); function get_zero_index(array $array, &$result = []) { foreach($array as $i => $v) { if ($i === 0 && is_string($v)) { $result[] = $v; } elseif(is_array($v)) { get_zero_index($v, $result); } } return $result; } print_r(get_zero_index($v));
Output for 7.1.0 - 7.1.20, 7.2.0 - 7.2.33, 7.3.16 - 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 - 8.3.31, 8.4.1 - 8.4.22, 8.5.0 - 8.5.7
Array ( [0] => ccrs_date [1] => prelim_title_report_date [2] => additional_escrow_deposit_date [3] => earnest_money_date [4] => acceptance_date [5] => contract_date [6] => prelim_title_report_date )

preferences:
102.32 ms | 1467 KiB | 4 Q