How to check if object has any properties in JavaScript?

Question

Assuming I declare

var ad = {}; 

How can I check whether this object will contain any user-defined properties?

Answer 1

Very late answer, but this is how you could handle it with prototypes.

Array.prototype.Any = function(func) {
    return this.some(func || function(x) { return x });
}

Object.prototype.IsAny = function() {
    return Object.keys(this).Any();
}