Hence typeof window.alert=="function" || window.alert instanceof Function returns false. You can still test for such functions in IE6 by first checking if it's a host object and then by testing if its …

In Java, you can use instanceOf or getClass() on a variable to find out its type. How do I find out a variable's type in JavaScript which isn't strongly-typed? For example, how do I know if the b...

In my particular case: callback instanceof Function or typeof callback == "function" does it even matter, what's the difference? Additional Resource: JavaScript-Garden typeof vs instanceof

Nov 12, 2015 · The typeof works sufficiently well with primitive values except null.typeof cannot distinguish between null & object because null is falsy & objects are truthy.Here are which may …

May 9, 2010 · In JavaScript typeof is an operator and a function. Is it better used as an operator or a function? Why?

Feb 16, 2017 · Given everything is an object in Javascript (including arrays, functions & primitive data type objects), I find this behaviour of the typeof operator very inconsistent. Can someone …

Sep 24, 2010 · Note that the typeof operator does always return "object" for the this scope of a function (unless the scope happens to be a function). See "Why does typeof this return “object”?"

May 2, 2011 · I need to loop over the properties of a javascript object. How can I tell if a property is a function or just a value? var model = { propertyA: 123, propertyB: function () { return 456; }...

May 16, 2018 · 3 Cause x is an object that inherits call from Function.prototype, however call is meant to be called on a function, therefore it fails if you try to execute it on a plain object.

Jun 14, 2013 · There is no reason not to use typeof. Not only is it faster but the ECMAScript specification ensures that all functions have a type of "function" and that only functions can …