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In VB.NET, the C# variant of "typeof" should be translated into the VB.NET's GetType method. The TypeOf keyword in VB.NET is used to compare an object reference variable to a data type. The following example uses TypeOf...Is expressions to test the type compatibility of two object reference variables with various data types.
Python allows the creation of class methods and static methods via the use of the @classmethod and @staticmethod decorators. The first argument to a class method is the class object instead of the self-reference to the instance. A static method has no special first argument. Neither the instance, nor the class object is passed to a static method.
Variables in standard JavaScript have no type attached, so any value (each value has a type) can be stored in any variable. Starting with ES6 , the 6th version of the language, variables could be declared with var for function scoped variables, and let or const which are for block level variables.
In JavaScript, object creation is prototype-based instead: an object creating function can have a prototype property, and any object assigned to that property will be used as a prototype for the objects created with that function. The Prototype framework is not to be confused with this language feature.
When a function is attached as a property of an object and called as a method of that object (e.g. obj.f(x)), this will refer to the object that the function is contained within. [14] [15] It is even possible to manually specify this when calling a function, by using the .call() or .apply() methods of the function object. [16]
The methods of this object are callbacks. In PL/I and ALGOL 60 a callback procedure may need to be able to access local variables in containing blocks, so it is called through an entry variable containing both the entry point and context information.
The method Print in class Box, by invoking the parent version of method Print, is also able to output the private variables length and width of the base class. Otherwise, these variables are inaccessible to Box. The following statements will instantiate objects of type Rectangle and Box, and call their respective Print methods:
The initial design is encouraged to use the most restrictive visibility possible, in order of local (or method) variables, private variables (in object oriented programming), and global (or public) variables, and only be expanded when and as much as necessary. This prevents changes to visibility from invalidating existing code. [43]