How does JavaScript compare two arrays?

Source: Internet
Author: User

How does JS compare two arrays with exactly the same elements?
JavaScript can not directly use = = or = = = To determine whether two arrays are equal, whether equal or congruent, the following two lines of JS code will return false

<script type= "Text/javascript" > alert ([]= =[]); Alert ([]= = =[]); </script>

To determine whether the two arrays in JS are the same, you need to convert the array to a string before comparing it. The following two lines of code will return true

<script type= "Text/javascript" > alert ([].tostring ()= = [].tostring ()]; Alert ([].tostring ()= = = =[].tostring ()]); </script>

JS to compare two arrays have the same element, that is, two arrays all elements are the same, but the order of the elements is not necessarily consistent. You only need to sort the array first, and then compare the two arrays for equality.

Try comparing the following two lines of code:

<script type= "Text/javascript" > alert ([1,2,3].tostring () = = [3,2,1].tostring ()); Alert ([1,2,3].sort (). ToString () = = [3,2,1].sort (). ToString ()); </script>

How does JavaScript compare two arrays?

Related Article

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.