how to check if a form is valid programmatically using jQuery Validation Plugin

Use .valid() from the jQuery Validation plugin:

$("#form_id").valid();

Checks whether the selected form is valid or whether all selected elements are valid. validate() needs to be called on the form before checking it using this method.

Where the form with id='form_id' is a form that has already had .validate() called on it.

2015 answer: we have this out of the box on modern browsers, just use the HTML5 CheckValidity API from jQuery. I've also made a jquery-html5-validity module to do this:

npm install jquery-html5-validity

Then:

var $ = require('jquery')
require("jquery-html5-validity")($);

then you can run:

$('.some-class').isValid()

true