localStorage.prototype is null

Question

I'm trying to extend localStorage w/ the following...

localStorage.prototype.setItem2 = function(key,value) {
    localStorage.setItem(key,value);
}

I'm getting "localStorage.prototype is null." Am I doing this correctly? Thanks!

Answer 1

localStorage is an instance of the Storage object. Try Storage.prototype.setItem2 or Object.getPrototypeOf(localStorage).setItem2

Answer 2

You can directly set it by :

localStorage.setItem2 = function(key, value) {
    // do something
}

or use Storage.prototype

Before you do so, make sure you are not overwriting any existing property. This is to prevent any overwriting for future enhancements to the API by the browsers.

Answer 3

LocalStorage and sessionStorage Objects implements from Storage Interface.

You can extend the Storage through prototype.

Storage.prototype.removeItems = function () {
  for(item in arguments) {
    this.removeItem(arguments[item]);
  }
};

Refer to Article: HTML5: Storage APIs