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

You can use the built in Object.keys method to get a list of keys on an object and test its length.

var x = {};
// some code where value of x changes and than you want to check whether it is null or some object with values

if(Object.keys(x).length > 0){
 // Your code here if x has some properties  
}