Fastest way to get the first n elements of a List into an Array

Question

What is the fastest way to get the first n elements of a list stored in an array?

Considering this as the scenario:

int n = 10;
ArrayList<String> in = new ArrayList<>();
for(int i = 0; i < (n+10); i++)
  in.add("foobar");

Option 1:

String[] out = new String[n];
for(int i = 0; i< n; i++)
    out[i]=in.get(i);

Option 2:

String[] out = (String[]) (in.subList(0, n)).toArray();

Option 3: Is there a faster way? Maybe with Java8-streams?

Answer 1

Option 1 Faster Than Option 2

Because Option 2 creates a new List reference, and then creates an n element array from the List (option 1 perfectly sizes the output array). However, first you need to fix the off by one bug. Use < (not <=). Like,

String[] out = new String[n];
for(int i = 0; i < n; i++) {
    out[i] = in.get(i);
}