Is object empty? [duplicate]

Answer 1

I modified Sean Vieira's code to suit my needs. null and undefined don't count as object at all, and numbers, boolean values and empty strings return false.

'use strict';

// Speed up calls to hasOwnProperty
var hasOwnProperty = Object.prototype.hasOwnProperty;

var isObjectEmpty = function(obj) {
    // null and undefined are not empty
    if (obj == null) return false;
    if(obj === false) return false;
    if(obj === true) return false;
    if(obj === "") return false;

    if(typeof obj === "number") {
        return false;
    }   
    
    // Assume if it has a length property with a non-zero value
    // that that property is correct.
    if (obj.length > 0)    return false;
    if (obj.length === 0)  return true;

    // Otherwise, does it have any properties of its own?
    // Note that this doesn't handle
    // toString and valueOf enumeration bugs in IE < 9
    for (var key in obj) {
        if (hasOwnProperty.call(obj, key)) return false;
    }
    
    
    
    return true;
};

exports.isObjectEmpty = isObjectEmpty;