It will take you to some of the most important topics for Java and JEE interviews, worth reading even if you are not preparing for Java interview. I am sure you have seen many of these questions personally on your interviews and many of you would have answered them correctly as well.
Pre-Java 8 you should use: The problem with arrays is that a remove operation can take O n time to complete. Really in Java this is an array copy of the remaining elements being moved to replace the empty spot.
Many other solutions offered here will trigger this issue. And iterates the list. When it hits a null, it simply iterates the read position by 1. When they are the same it passes, when they are different it keeps moving along copying the values.
Then at the end it trims to size. It effectively does this internally: The only thing that could ever be faster is if you iterated the list from both ends, and when you found a null, you set its value equal to the value you found at the end, and decremented that value.
And iterated until the two values matched. You'd mess up the order, but would vastly reduce the number of values you set vs. Which is a good method to know but won't help much here as.
It does an System. Here we not only iterate the list. We reiterate the entire list, each time we match the null. You could quite literally, sort the entire collection between items with values and items with null values and trim the ending in less time.
In fact, that's true for all the broken ones. At least in theory, the actual system. In theory, theory and practice are the same thing; in practice they aren't.CopyOnWriteArrayList in Java is also an implementation of the List interface but it is a thread safe variant.
This thread safety in CopyOnWriteArrayList is achieved by making a fresh copy of the underlying array with every mutative operations.
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Oct 02, · Last Updated Date: 2nd March Time is changing and so is Java interviews. Gone are the days, when knowing the difference between String and StringBuffer can help you to go through the second round of interview, questions are becoming . Description: Here we can see example for copying all content of ArrayList to an array.
You can get this done by calling toArray() method. Java ArrayList copy. Ask Question.
up vote down vote favorite. I have an ArrayList l1 of size I assign l1 to new list reference type l2. nowhere in java-api deep cloning is done by any collection class – Vikash May 5 at This answer doesn't make a whole lot of sense.
ZoomButton: This class was deprecated in API level Use other means to handle this functionality. This widget is merely a simple wrapper around a long-press handler.