Which is better arraylist or vector

Fun fact: The Stack of Java1. Show 3 more comments. If you don't need something explitly apparent in Vector , use ArrayList. Oli Oli k 62 62 gold badges silver badges bronze badges. Over three years on now, I can't point you to exactly what I was talking about but there are plenty of benchmarks out there. It's not until threading where you see the biggest jumps but here's one: javacodegeeks.

If you have a benchmark that writes only once and then performs reads only will deliver a different result — Tobi. Please provide an evidence to your data — wiredmark. Since the vector is synchronised and arraylist is not synchronised, that may be a reason, arraylist are faster than vector. There are 2 major differentiation's between Vector and ArrayList.

Other than this, there are some practical differences between them, in terms of programming effort: To get the element at a particular location from Vector we use elementAt int index function. This function name is very lengthy. In place of this in ArrayList we have get int index which is very easy to remember and to use.

Similarly to replace an existing element with a new element in Vector we use setElementAt method, which is again very lengthy and may irritate the programmer to use repeatedly. In place of this ArrayList has add int index, object method which is easy to use and remember. Like this they have more programmer friendly and easy to use function names in ArrayList. When to use which one? Try to avoid using Vectors completely. ArrayLists can do everything what a Vector can do.

More over ArrayLists are by default not synchronized. If you want, you can synchronize it when ever you need by using Collections util class. ArrayList has easy to remember and use function names. Hope it helps. Wrong info switched on grow size for ArrayLIst and Vector, otherwise quite good answer. The grow of Vector is doubling with needed docs. I don't understand how the method name can be a criteria for using or not using that method.

ArrayList - ArrayList is not synchronized. ArrayList is not a legacy class, it is introduced in JDK 1. ArrayList is fast because it is non-synchronized. ArrayList uses Iterator interface to traverse the elements. It is a good habit to construct the ArrayList with a higher initial capacity.

This can avoid the resizing cost. As shown in the examples above, they are similar to use. The real difference is their underlying implementation and their operation complexity.

Vector is almost identical to ArrayList, and the difference is that Vector is synchronized. Because of this, it has an overhead than ArrayList. Normally, most Java programmers use ArrayList instead of Vector because they can synchronize explicitly by themselves. The time complexity comparison is as follows:. The difference of their performance is obvious.

LinkedList is faster in add and remove, but slower in get. Based on the complexity table and testing results, we can figure out when to use ArrayList or LinkedList.

In brief, LinkedList should be preferred if:. I believe the add of an ArrayList has amortized complexity of O 1 because it has to double the array every time the buffer is full and we do an add; however, the LinkedList is just O 1 assuming the linkedlist keeps track of the tail of the list.

I just run the given program and found unexpected result in case of add element in arraylist and linkedlist. Add in linkedlist taking much time then array list. I was amazed looking the results. So I run only add section removing other get, remove , getting expected result.

Angular 7. Machine Learning. Data Structures. Operating System. Computer Network. Compiler Design. Computer Organization. Discrete Mathematics. Ethical Hacking. Any method that touches the Vector 's contents is thread safe. ArrayList , on the other hand, is unsynchronized, making them, therefore, not thread safe. With that difference in mind, using synchronization will incur a performance hit. So if you don't need a thread-safe collection, use the ArrayList.

Why pay the price of synchronization unnecessarily? Internally, both the ArrayList and Vector hold onto their contents using an Array. You need to keep this fact in mind while using either in your programs. When you insert an element into an ArrayList or a Vector , the object will need to expand its internal array if it runs out of room.

A Vector defaults to doubling the size of its array, while the ArrayList increases its array size by 50 percent. Depending on how you use these classes, you could end up taking a large performance hit while adding new elements. It's always best to set the object's initial capacity to the largest capacity that your program will need. By carefully setting the capacity, you can avoid paying the penalty needed to resize the internal array later.