Arraylist and vector, hashmap, and hashtable

Source: Internet
Author: User

From API:

1. arraylist and vector:

Original article: this class (arraylist) is roughly equivalent to vector, doesn t that it is unsynchronized.

Arraylist is not synchronized, and vector is synchronized. In a multi-threaded environment, vector is safer. If thread security is not required in the program, we recommend that you use arraylist instead of vector.

 

2. hashmap and hashtable:

Original article: The hashmap class is roughly equivalent to hashtable, doesn't that it is unsynchronized and permits nulls.

Hashmap can be considered as hashtable, except for not synchronizing and allowing null values as key values and element values. Hashtable does not allow null values as key values and element values.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.