localStorage_extension.js

(()=>{
    const localStorage_extension = (function(){
        this._get = (label=>{
            return JSON.parse(localStorage.getItem(label));
        });

        this._put = ((label,items)=>{
            return localStorage.setItem(label,JSON.stringify(items));
        });

        this._push = ((label, item)=>{
            var arr;

            if(typeof this._get(label) !== 'object') {
                arr = [];
            } else {
                arr = this._get(label);
            }

            if(arr.indexOf(item) < 0)            arr.push(item);

            return this._put(label,arr);
        });

        this._pop = ((label)=>{
            var items, r;

            items = this._get(label);
            r = items.pop();
            this._put(label,items);

            return r;
        });
        
        this._find = ((label,item)=>{
            var lb = this._get(label);
            var i = lb.indexOf(item);
            return (i < 0 ? false : lb[i]);
        });
    });

    window.lstore = new localStorage_extension();
})();