How JavaScript determines the number of checkboxes selected in a form _javascript tips

This example describes how JavaScript determines the number of multiple-selection box checkboxes in a form. Share to everyone for your reference. Specifically as follows:

This uses JavaScript to detect and determine the number of selected boxes in the form, that is, how many checkboxes have been selected, in the past, this issue is often asked by the major forums, because the detection checkbox is not as simple as the detection of the input box, especially the number of judgments are often encountered, So think that this JS code is still very useful, we are interested in the perfect again.

The effect is as shown in the following illustration:

The online demo address is as follows:

http://demo.jb51.net/js/2015/js-checkbox-chk-num-codes/

The specific code is as follows:

<! DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 transitional//en" "Http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd ">  

The

wants this article to help you with your JavaScript programming.