Java if statement exception [on hold]

Define a List<Object> myList and put something in it so that its size is 1, and I print it out to make sure the size is actually 1.

Then for the following codes:

if(myList != null && myList.size() > 0){
     print sth here
}

Then console shows nothing. Why? Since the size of myList is one.

But when I do this:

if (myList.size()>0){
    print sth here
}

Then console do show something. What's the issue here?