如何删除特定的sessionStorage值并同时减少另一个sessionStorage值

Question

我想知道如何从密钥worker中删除特定的sessionStorage值，并将密钥limit值减1，而不会在每次删除特定密钥工作时影响其他sessionStorage值？

这是我的Jsfiddle https://jsfiddle.net/d7e92k5d/2/

HTML

<ul>
    <li>
        <div class="worker-container-last">
            <label class="worker-label"><input type="text" class="first-name" /></label>
        </div>
        <div class="worker-container-last">
            <label class="worker-label"><input type="text" class="last-name" /></label>
        </div>
        <div class="worker-container-last">
            <label class="worker-label">
                <select name="title[]" class="title">
                    <option value="Select a Title" selected="selected">Select a Title</option>
                    <option value="Boss">Boss</option>
                    <option value="Worker">Worker</option>
                    <option value="Manager">Manager</option>
                </select>
            </label>
        </div>
        <div class="add-more"></div>
        <div><a class="worker" title="" href="">Add Another Worker</a></div>
    </li>
</ul>

JQuery

var worker_record = [];
$(document).ready(function(){
    new_worker();
    $('.worker').on('click', function(e){
        e.preventDefault();
        e.stopPropagation();

        if(sessionStorage.getItem("limit") === null){
            sessionStorage.setItem('limit', 0);
        }

        if(sessionStorage.getItem('limit') <= 2){
            var first_name = $('.first-name').val();
            var last_name = $('.last-name').val();
            var title = $('.title:first').val();            

            var tblObj = {first_name: first_name, last_name: last_name, title: title};
            worker_record.push(tblObj);

            sessionStorage.worker = JSON.stringify(worker_record);
            new_worker();

            var count = sessionStorage.getItem('limit');
            count++;
            sessionStorage.setItem('limit', count);  
        }
    });

    function new_worker(){
        var max_fields = 3;
        var x = 0;

        if(!(typeof sessionStorage.worker === 'undefined' || sessionStorage.worker.length<1)){
            worker_record = JSON.parse(sessionStorage.worker);
        }

        $('.add-more').empty();
        for(var i=0; i<worker_record.length; i++){
            if(x < max_fields){
                x++;
                var first_name = worker_record[i].first_name;
                var last_name = worker_record[i].last_name;
                var title = worker_record[i].title;

                var worker = '<div class="worker-container"><div class="delete-worker"><a title="" href="#">Delete</a></div><div class="update-worker"><a title="" href="#">Update</a></div><div class="worker-box"><label class="another-worker"><input type="text" name="workers_first_name[]" class="first-name" value="' + first_name + '" /></label></div><div class="worker-box"><label class="another-worker"><input type="text" name="workers_last_name[]" class="last-name" value="' + last_name + '" /></label></div><div class="worker-box-last"><label class="another-worker"><select name="workers_title[]" class="title workers-title-options"><option value="Select a Title" selected="selected">Select a Title</option><option value="Boss">Boss</option><option value="Worker">Worker</option><option value="Manager">Manager</option></select></label></div></div>';

                $('.add-more').append(worker);
                $('.title:eq('+$('.workers-title-options').length+')').val(title);
            }
        }

        $('.first-name:first').val('');
        $('.last-name:first').val('');
        $('.title:first').val('Select a Title');
    }

    $('.add-more').on('click', '.delete-worker', function(e){
        e.preventDefault();
        e.stopPropagation();    

        $(this).parent('div').remove();
        worker_record = JSON.parse(sessionStorage.worker);
        worker_record.splice(worker_record.length -1, 1);
        sessionStorage.worker = JSON.stringify(worker_record);
    });
});