array(3) { [0]=> string(5) "Volvo" [1]=> string(3) "BMW" [2]=> string(6) "Toyota" }
The same goes for associative arrays, you can declare the array first, and then add items to it:
array(3) { ["brand"]=> string(4) "Ford" ["model"]=> string(7) "Mustang" ["year"]=> int(1964) }