Time complexity for java ArrayList

by

An ArrayList in Java is a List that is backed by an array.

The get(index) method is a constant time, O(1), operation.

The code straight out of the Java library for ArrayList.get(index):

public E get(int index) {
    RangeCheck(index);
    return (E) elementData[index];
}

Basically, it just returns a value straight out of the backing array. (RangeCheck(index)) is also constant time)

More Related Contents:

  1. Time complexity of contains(Object o), in an ArrayList of Objects
  2. NumberFormatException not wrking java
  3. Write a program that takes an array/arraylist of integer and finds longest sub array/arraylist whose entries are equal [closed]
  4. How to create a Java ArrayList in C
  5. Exception in thread “main” java.lang.IndexOutOfBoundsException: Index: 6, Size: 6 [duplicate]
  6. Why do I get an UnsupportedOperationException when trying to remove an element from a List?
  7. Convert list to array in Java [duplicate]
  8. Java List.add() UnsupportedOperationException
  9. Time complexity of Java’s substring()
  10. Moving items around in an ArrayList
  11. Stream Filter of 1 list based on another list
  12. Trouble with Gson serializing an ArrayList of POJO’s
  13. Finding duplicate values in arraylist
  14. Creating an Arraylist of Objects
  15. Empty an ArrayList or just create a new one and let the old one be garbage collected? [duplicate]
  16. Simple way to compare 2 ArrayLists
  17. Hash Set and Array List performances
  18. Scanner skipping every second line from file [duplicate]
  19. ArrayList: how does the size increase?
  20. Add an object to an ArrayList and modify it later
  21. Check if an ArrayList contains every element from another ArrayList
  22. Adding to an ArrayList Java
  23. Can not deserialize instance of java.util.ArrayList out of VALUE_STRING
  24. Merging two arrayLists into a new arrayList, with no duplicates and in order, in Java
  25. Time Complexity for Java ArrayList
  26. How to declare an ArrayList with values? [duplicate]
  27. Better way to find index of item in ArrayList?
  28. Java generics – ArrayList initialization
  29. How to pass ArrayList using putStringArrayListExtra()
  30. What is the difference between ArrayList.clear() and ArrayList.removeAll()?

Leave a Comment