What Javascript types can have properties? -

What is the best way to determine whether X can have an asset? Can I just do

if (x example object)

Is it enough to make sure that there can be properties in X or Do I need to check anything else? I know that there are no qualities in the ancient properties, but is there anything else? I am checking various types:

  var a = false; A.foo = "bar"; Console.log (a ["foo"]); // logs undefined var b = "b"; Bfu = "bar"; Console.log (b ["foo"]); // logs undefined var c = new array (1,2,3); C.foo = "bar"; Console.log (c ["foo"]); // log time var d = new object (); D.foo = "bar"; Console.log (d ["foo"]); // log time var e = new regx (""); E.foo = "foo"; Console.log (d ["bar"]); // log time var f = new number (1); F.foo = "bar"; Console.log (f ["foo"]); // log time var g = function () {}; G. Fu = "bar"; Console.log (g ["foo"]); // log bar   
 etc.   
 
 
 Yes, that's quite a lot. Note: You can also accept  string  properties, which you are not checking:  
  var a = new string ("hello"); A.foo = "bar";   
 But since  the origin of the string == true  you should be OK.  
 For fun, try it (this works, because  / x / installation object == true ):  
  var x = / Hello /; X.foo = "bar";   
 Another note: Your  example  check will catch it, but I want you to know that normal one javascript  function   object , a closure  (function () {}) ()  is not  required  a  object , but it does not < may be   
 -tjw