This script exposes serialize and unserialize functions that very closely mimic PHP's corresponding functions. It handles ints, floats, strings, booleans, nulls, and arrays. No custom objects or classes.
// string serialize(mixed);
var fruit = ["apples", "oranges", "bananas"];
var s = serialize(fruit);
alert(s);
// outputs:
a:3:{i:0;s:6:"apples";i:1;s:7:"oranges";i:2;s:7:"bananas";}
// mixed unserialize(string);
var obj = unserialize(s);
alert(s);
// outputs
apples,oranges,bananas