Menu
Assuming I have an ArrayList of ArrayLists created in this manner:
ArrayList< ArrayList<String> > listOfListsOfStrings =
new ArrayList< ArrayList<String> >();
If I call:
listOfListsOfStrings.clear();
Will an attempt to later access any of the Strings inside listOfListsOfStrings always result in a java.lang.NullPointerException?
909
clear() method removes all of the elements from this list. The list will be empty after this call returns.
clear() deletes every element from the collection and removeAll() one only removes the elements matching those from another Collection.
The clear() method of List interface in Java is used to remove all of the elements from the List container. This method does not deleted the List container, instead it justs removes all of the elements from the List. Parameter: This method accepts does not accepts any parameter.
The Java ArrayList removeAll() method removes all the elements from the arraylist that are also present in the specified collection. The syntax of the removeAll() method is: arraylist. removeAll(Collection c);
No, just the references will be cleared. If no reference to an object exists anymore it might be garbage collected, but you'd get no NPE, since you then have no way to get a new reference to that object anyway.
160
No, it will not delete objects in the ArrayList if you still have external references to them. ArrayList.clear() does nothing to the objects being referred to unless they are orphaned, in which case you won't be referring to them later on.
31
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
