Condition 'customArray == null' is always 'false' when reached in Java?

Question

Java

If the object check customArrayin the method looks like this, when first it checks for size and then for null , then the compiler issues a warning likecustomArray.length() == 0customArray == null

Condition 'customArray == null' is always 'false' when reached

. But if we swap the check in such a way that first there is a check for null , and then for size , then the warning disappears. Why is that?customArray == nullcustomArray.length() == 0

@Override
    public int findMinValueMethodStream(CustomArray customArray) throws ArrayException {
        if(customArray.length() == 0 || customArray == null) {
            LOGGER.log(Level.ERROR, "CustomArray object is empty or null!");
            throw new ArrayException("CustomArray object is empty or null!");
        }
// some code
}

The **CustomArray** class is just a wrapper class over int[] array.

Answer 1

Because conditions are checked from left to right.
Therefore, it makes no sense to check customArray for null second - if the array is not null, then it will not come to it; if it is null, then execution will fail with NPE.
But it just makes sense to swap them - first we check if customArray is null, and only if not, then we turn to the object, asking for its size.