Multiple inheritance

Multiple inheritance is where a child inherits from more than one parent. Some OO languages support multiple inheritance out of the box and some don't. You can argue both ways, that multiple inheritance is convenient or that it's unnecessary, complicates application design, and it's better to use an inheritance chain instead. Leaving the discussion of multiple inheritance's pros and cons for the long, cold winter nights, let's see how you can do it in practice in JavaScript.

The implementation can be as simple as taking the idea of inheritance by copying properties and expanding it so that it takes an unlimited number of input objects to inherit from.

Let's create a multi() function that accepts any number of input objects. You can wrap the loop that copies properties in another loop that goes through all the objects passed as arguments to the function:

    function multi() { 
      var n = {}, stuff, j = 0, len = arguments.length; 
      for (j = 0; j <len...