What does Date() for example return ?

What's the output? console.log({} + {});

function base(callback){ callback.call({msg:'hi'}) } function message(){ alert(this.msg) }; base(message); which is the value of alert?

Choose correct answer: 'If you delete an object prototype property, it will..........'

What is the use of isNaN function

What does Object.keys(x) return given the following x object. var x = { 'a': 1, 'b': 2 };

Which code snippet removes objects from an associative array?

Which one shows the correct result for the code below? var arr = []; arr[0] = 'Jani'; arr[1] = 'Hege'; arr[2] = 'Stale'; arr[3] = 'Kai Jim'; arr[4] = 'Borge'; console.log(arr.join()); arr.splice(2, 0, 'Lene'); console.log(arr.join());

Which will invoke the browser's Add To Favorite dialog box?

Which declaration is not valid?

What does the following JavaScript code do?