Is this a question from a mock exam? If so, make sure (please) to tell us where it is from.
Probably because Java evaluates expressions from left to right. It starts with array[index], at which point index is 0. Then it tries to assign that value, and assigns it to the value of the expression to the right of the first =.
Joined: Jul 10, 2009
and the question is not from any mock exam
Joined: Oct 13, 2005
Now, everybody else, tell me whether I got it wrong!