DOM - get list of classes, convert to CSS selector

class-list.js

jQuery(function($){
var classes = [];
$('.page-id-x [class]').each(function(){
    $($(this).attr('class').split(' ')).each(function() { 
        if (this.length>0 && $.inArray(this.valueOf(), classes)==-1) {
            classes.push( '.' + this.valueOf() );
        }    
    });
});
console.log("LIST START\n\n"+ classes.join('{}' + '\n')+"\n\nLIST END");


});

You can use this function to get a list of classes on the page out of the DOM in CSS format. Change .page-id-x on Line 3 to adjust the outermost div that will be checked before moving down the DOM tree.

Then just paste it into the Console and hit Enter.