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<?php $select = [ 'foo', 'bar', [ 'size' => 128, 'type' => 'png' ], 'baz', 'qux' ]; function convert($in) { $out = []; for ($i = 0, $m = count($in); $i < $m; $i++) { $current = $in[$i]; $next = $in[$i + 1] ?? null; if (!is_string($current)) { throw new \Exception('Malformed field list.'); } if (is_array($next)) { $out[$current] = $next; $i++; } else { $out[$current] = true; } } return $out; } var_dump(convert($select));

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