- 1 Why ArrayList is not efficient for manipulation?
- 2 Which iterator is slower than ArrayList?
- 3 Is linked list faster than ArrayList?
- 4 Why Searching is fast in ArrayList?
- 5 Can ArrayList hold duplicates?
- 6 Which is faster array or ArrayList?
- 7 How can we remove an object from ArrayList?
- 8 Which is the faster and uses less memory?
- 9 What is the default capacity of ArrayList?
- 10 Is ArrayList linked list?
- 11 Does ArrayList maintain order?
- 12 Is ArrayList thread safe?
- 13 Which is faster ArrayList or HashMap?
- 14 When should we use ArrayList?
- 15 Which is faster ArrayList or HashSet?
Why ArrayList is not efficient for manipulation?
ArrayList is worst choice if our operation is insertion and deletion in the middle because internally several shift operations are performed. In ArrayList elements will be stored in consecutive memory locations hence retrieval operation will become easy.
Which iterator is slower than ArrayList?
LinkedList is faster than ArrayList for deletion. ArrayList’s slower since the internal backing-up array needs to be reallocated. Deletion time for ArrayList: Access time + O(n). Deletion time for LinkedList: Access time + O(1).
LinkedList is faster than ArrayList while inserting and deleting elements, but it is slow while fetching each element.
Why Searching is fast in ArrayList?
ArrayList Vs LinkedList
- 1) Search: ArrayList search operation is pretty fast compared to the LinkedList search operation.
- Reason: ArrayList maintains index based system for its elements as it uses array data structure implicitly which makes it faster for searching an element in the list.
Can ArrayList hold duplicates?
ArrayList allows duplicate values while HashSet doesn’t allow duplicates values. Ordering: ArrayList maintains the order of the object in which they are inserted while HashSet is an unordered collection and doesn’t maintain any order.
Which is faster array or ArrayList?
The capacity of an Array is fixed. Whereas ArrayList can increase and decrease size dynamically. Whereas ArrayList can hold item of different types. An array is faster and that is because ArrayList uses a fixed amount of array.
How can we remove an object from ArrayList?
There are two way to remove an element from ArrayList.
- By using remove () methods: ArrayList provides two overloaded remove () method. a.
- remove (int index): Accept index of object to be removed. b.
- remove (Obejct obj): Accept object to be removed.
Which is the faster and uses less memory?
Sqldatareader is fast as compare to Dataset. Because it stored data in forward only and also stores only one record at a time. And dataset stores all records at the same time. This is the reason, SqlDataReader is faster than Dataset.
What is the default capacity of ArrayList?
Whenever an instance of ArrayList in Java is created then by default the capacity of Arraylist is 10. Since ArrayList is a growable array, it automatically resizes itself whenever a number of elements in ArrayList grow beyond a threshold.
ArrayList is essentially an array. LinkedList is implemented as a double linked list. The get is pretty clear. O(1) for ArrayList, because ArrayList allow random access by using index.
Does ArrayList maintain order?
Yes, ArrayList is an ordered collection and it maintains the insertion order.
Is ArrayList thread safe?
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.
Which is faster ArrayList or HashMap?
While the HashMap will be slower at first and take more memory, it will be faster for large values of n. The reason the ArrayList has O(n) performance is that every item must be checked for every insertion to make sure it is not already in the list. We will do n insertions, so it is O(n^2) for the whole operation.
When should we use ArrayList?
ArrayList provides constant time for search operation, so it is better to use ArrayList if searching is more frequent operation than add and remove operation. The LinkedList provides constant time for add and remove operations. So it is better to use LinkedList for manipulation.
Which is faster ArrayList or HashSet?
This quick write-up explains the performance of the contains() method of the HashSet and ArrayList collections. As a conclusion, we can learn, that the contains() method works faster in HashSet compared to an ArrayList.