How to concatenate the two array values i.e. [first-name] and [last-name]

I have a scenario where I do not have to use GROUP_CONCAT MySQL Function, there are two array which has first_name and last_name stored in it.

Current Array:

first-name = ['sam', 'john', 'tom'];
last-name = ['lath', 'mathhew'];

Expected Array = ['sam lath', 'john matthew', 'tom'];