Combine Individual Items From Separate Arrays Into a Third Array

I have two arrays, one with a list of first names and a second with a list of last names. What I would like to do is combine the first name and the last name that reside at the same index position in their respective arrays into a third array. Each pair of arrays will always have the same number of items, but that number may change - i.e., in some instances there may be 5 first names and 5 last names, but at other times there may be 15 first names and 15 last names.

So, for example:

Array $firstName contains:
$firstName[0] = Jon
$firstName[1] = Bob
$firstName[2] = Tom

Array $lastName contains:
$lastName[0] = Smith
$lastName[1] = Jones
$lastName[2] = White

And I want to create array $fullName like this…
$fullName[0] = Jon Smith
$fullName[1] = Bob Jones
$fullName[2] = Tom White

Thanks for the help.

PS C:\> $firstName = @("Jon","Bob","Tom")
PS C:\> $lastName = @("Smith","Jones","White")
PS C:\> 0..($firstName.Count - 1) | ForEach-Object {$fullName += @("$($firstName[$_]) $($lastName[$_])")}
PS C:\> $fullName
Jon Smith
Bob Jones
Tom White

Works great! Thanks for the help Curtis!