Defining a new object in Javascript is pretty easy - but what if you want to find out if it's empty? For example, is an empty object, but how do we test that this is the case? {} actually let myObject = {} The easiest (and best) way to do this, is to use . Object.keys() This method turns all the keys in an object to an array, which we can then test the length of: let myObject = {} console.log(Object.keys(myObject).length) // Returns 0! But wait... Javascript is well known for how it handles types strangely - and new constructors return an object with length 0: let myFunction = function() { console.log("hello") } console.log(Object.keys(new myFunction()).length) Fortunately, we can check if something is an object by checking its property: constructor console.log(function myFunction() {}.constructor) // Function console.log({}.constructor) // Object Therefore, we can check if an is empty if its constructor is an , and it has an value of : object Object Object.keys() 0 let empty = {} let isObjEmpty = (obj) => { return Object.keys(obj).length === 0 && obj.constructor === Object } console.log(isObjEmpty(empty)); // Returns true, Object is empty!
