Shulou(Shulou.com)06/02 Report--

What is the comparison and application scenario of list in java integration system? in order to solve this problem, this article introduces the corresponding analysis and solution in detail, hoping to help more partners who want to solve this problem to find a more simple and feasible method.

Differences and applicable scenarios between list, Set and Map

1. List,Set inherits from Collection interface, but Map is not.

2. List features: elements have put order, elements can be repeated, Set characteristics: elements do not put in order, elements can not be repeated, repeating elements will be covered. (note: although elements do not put in order, the position of elements in set is determined by the HashCode of the element, and its position is actually fixed. The Object that adds Set must define the equals () method, and list supports the for loop, that is, traversing through subscript. You can also use iterators, but set can only use iterations because he is out of order and cannot use subscripts to get the desired value. )

Comparison of 3.Set and List:

Set: the retrieval of elements is inefficient, deletion and insertion are efficient, and insertions and deletions do not cause changes in the location of elements.

List: similar to arrays, List can grow dynamically, with high efficiency in finding elements and low efficiency in inserting and deleting elements, because it causes other elements to change their positions.

4.Map is suitable for storing data of key-value pairs.

5. Thread-safe collection class and non-thread-safety collection class

LinkedList, ArrayList and HashSet are not thread-safe, while Vector is thread-safe

HashMap is not thread-safe, HashTable is thread-safe

StringBuilder is not thread-safe and StringBuffer is thread-safe.

Differences and applicable scenarios between ArrayList and LinkedList

Arraylist:

Advantages: ArrayList implements the data structure based on dynamic array, because the address is continuous, once the data is stored, the query operation will be more efficient (connected in memory).

Disadvantages: because the address is continuous, ArrayList has to move data, so insert and delete operations are relatively inefficient.

LinkedList:

Advantages: LinkedList is based on the linked list data structure, the address is arbitrary, so when opening up memory space does not need to wait for a continuous address, for the new and delete operations add and remove,LinedList have an advantage. LinkedList is suitable for scenes that need to be operated or inserted at a specified location.

Cons: because LinkedList moves the pointer, the performance of the query operation is relatively low.

Applicable scenario analysis:

ArrayList is selected when the data needs to be accessed, and LinkedList is used when the data needs to be added and deleted many times.

Differences and applicable scenarios between ArrayList and Vector

There are three construction methods for ArrayList:

Public ArrayList (int initialCapacity) / / constructs an empty list with the specified initial capacity.

Public ArrayList () / / constructs an empty list with an initial capacity of 10.

Public ArrayList (Collection

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.