In ES5, classes are written as functions, with instance methods assigned to
MyFunction.prototype. ES2015 allows us to use the simpler
class gives us built in instance functions, static functions, and inheritance.
constructor is a special function that is called automatically every time a class instance is created. We can use the
static keyword to declare static class functions. Static method calls are made directly on the class and cannot be called on instances of the class.
class gives us simple inheritance with the keyword
extends. Classes that inherit from a parent have access to respective parent functions via