Is the loop condition calculated each loop for "for" sentence in Java?

Question

This is my Java code:

List<Object> objects = new ArrayList();

// Assign values to objects
...

for (int i = 0; i < objects.size(); i++) {
    Object object = objects.get(i);
    ...
}

I have two questions:

1. Is objects.size() calculated only once before stating the loop, or is it calculated each loop?
2. If objects.size() is calculated each loop, then if other thread change it at the same time without multi-threads protection, the code may be crashed.

Am I correct?

Answer 1

Yes, it is calculated each time. If you have another thread altering the size of your objects list, the loop condition will keep changing.