Online PHP editor | refs for 60Kov

<?php $sales_people = array( '2' => array( 'states' => array('NY', 'NJ', 'CT', 'MA', 'VT', 'ME'), 'codes' => array('CA1', 'US7', 'UT9') ), '5' => array( 'states' => array('FL', 'GA', 'SC', 'NC', 'TN'), 'codes' => array('VA4', 'VA8', 'VA3') ) ); function populateLookup(array $sets): array { $lookup = []; foreach ($sets as $id => $haystacks) { foreach ($haystacks as $haystack) { $lookup += array_fill_keys($haystack, $id); } } return $lookup; } $map = populateLookup($sales_people); var_export($map); echo "\n---\n"; var_export($map['CT'] ?? null);