Imagine if you have the possibility to store large JSON returned from an AJAX call on the client. That’s now reality with the localStorage object in HTML5 and it can be accessed with something like this code:

localStorage.setItem(key, value);
alert(localStorage.getItem(key));

Can we store entire objects?

Yes there is a way extending a bit the logic of the code above. The localStorage in fact stores only strings, but what about arrays and objects. You can additionally use JSON global objects and its two methods – stringify and parse:

var a = JSON.stringify({name:'obj'});
alert(JSON.parse(a));

Do browsers support all that?

Of course … not! localStorage is supported by Firefox 3.5+, Chrome 2+, Safari 4+ and MSIE 8+. The solution is not to rely on browser version, but to check for object existence, and than to combine both techniques:

localStorage.setItem('a', JSON.stringify({ name : 'obj' }));
alert(JSON.parse(localStorage.getItem('a')));