How to check if an argument is an object (and not an array) in JavaScript

Question

After testing out instasnceof I found that it will return true if the argument is an array or an object literal.

function test(options){
  if(option         


        

Answer 1

function isPlainObject(o) {
     return Object(o) === o && Object.getPrototypeOf(o) === Object.prototype;
}

However, you can't test wether o was declared as a literal or instantiated somehow else - you can just test whether it's a plain object without any constructor than Object.