The following code uses a for loop to sum the elements of an array. Find the error(s) in the following code:

```
1 public void sumArray()
2 {
3 int[] numbers = new int[] { 1, 2, 3, 4, 5, 6, 7, 8 };
4
5 for ( int counter = 0; counter <= numbers.size; counter++ )
6 {
7 int sum += numbers[ counter ];
8 }
9 } // end method sumArray
```

The expression numbers.size should be numbers.length. Variable sum should be declared outside of the loop.