DRAFT
OutOfBoundsElementsAreNull
Misconception:
An access of an array element that is out of bounds (e.g., a[a.length])
produces null to indicate that the element does not exist.
Incorrect
Out-of-bounds array elements are null
Correct
Out-of-bounds array elements cannot be accessed
CorrectionHere is what's right.
Here is what's right.
Accessing an out-of-bounds element of an array throws an ArrayIndexOutOfBoundsException.
For example, in the following code, the while loop condition
is not a correct way to finish the loop.
a[i] will not produce null when i >= a.length;
instead the expression will throw an ArrayIndexOutOfBoundsException.
public int m(int[] a) {
int i = 0;
int sum = 0;
while (a[i] != null) { // error
sum += a[i];
i++;
}
return sum;
}Language
Java