Code:
var animals = { \"elephant\": { \"name\" : \"Bingo\", \"age\" :
Can't you use an array?
Anyway, in an object, you can do that:
Object.prototype.length = function() { var count = 0, k=null; for (k in this) { if (this.hasOwnProperty(k)) count++; } return count; } console.log( animals.length() );