How to zip multiple files in a folder by javascript

Question

I have been reading question posted, however i could not find reasonable answers.

What I want to do is zip selected files. The file are all pdf files. Here is html my code

<form role="form" id="download">
    <div id="all-folders-1" class="col-lg-6 col-md-6 col-sm-6 col-xs-12">
        <input name="pdfs" class="select pull-left" value="first.pdf" type="checkbox" style="margin-right:5px;"><b class="pull-left">Folder</b>
        <br/>
        <div class="all-folders-checkbox checkbox">
            <label>
                <input name="pdfs" class="entity" value="file1.pdf" type="checkbox">
                File 1
            </label>
        </div>
        <div class="all-folders-checkbox  checkbox">
            <label>
                <input name="pdfs" class="entity" value="file2.pdf" type="checkbox">
                File 2
           </label>
        </div>
        <div class="all-folders-checkbox  checkbox">
            <label>
                <input name="pdfs" class="entity" value="file3.pdf" type="checkbox">
                File 3
            </label>
        </div>
        <div class="all-folders-checkbox checkbox">
            <label>
                <input name="pdfs" class="entity" value="file4.pdf" type="checkbox">
                File 4
            </label>
        </div>
    </div>
</form>

And here I get selected checkbox by jquery.

var selected = [];
$('#download div input:checked').each(function() {
    selected.push($(this).attr('value'));
});

Basically I want to save each value .pdf in an array named selected. After that I dont know how to zip them in a folder by javascript. Or is that possible?