One of the weird behaviour and spec in Javascript is the typeof Array is Object. You can check if the variable is an array in couple of ways: var isArr = data instanceof Array; var isArr = Array.isArray(data); But the most reliable way is: isArr = Object.prototype.toString.call(data) == ‘[object Array]’; Since you tagged your question … Read more
(name is undefined) You: What is name? (*) JavaScript: name? What’s a name? I don’t know what you’re talking about. You haven’t ever mentioned any name before. Are you seeing some other scripting language on the (client-)side? name = null; You: What is name? JavaScript: I don’t know. In short; undefined is where no notion … Read more
All are different. typeof takes a type name (which you specify at compile time). GetType gets the runtime type of an instance. is returns true if an instance is in the inheritance tree. Example class Animal { } class Dog : Animal { } void PrintTypes(Animal a) { Console.WriteLine(a.GetType() == typeof(Animal)); // false Console.WriteLine(a is … Read more
C++11 update to a very old question: Print variable type in C++. The accepted (and good) answer is to use typeid(a).name(), where a is a variable name. Now in C++11 we have decltype(x), which can turn an expression into a type. And decltype() comes with its own set of very interesting rules. For example decltype(a) … Read more
There are two built-in functions that help you identify the type of an object. You can use type() if you need the exact type of an object, and isinstance() to check an object’s type against something. Usually, you want to use isinstance() most of the times since it is very robust and also supports type … Read more