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<?php $months = [ 'January', 'January', 'January', 'January', 'February' ]; $weeks = [ 'Week 1', 'Week 2', 'Week 3', 'Week 4', 'Week 1' ]; $newArray = array_map(function($index, $month) use ($weeks) { return $month . ' - ' . $weeks[$index]; }, array_keys($months), $months); print_r($newArray);

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