Object-Oriented JavaScript - Third Edition

Functions are data

Functions in JavaScript are actually data. This is an important concept that we'll need later on. This means that you can create a function and assign it to a variable, as follows:

    var f = function () { 
      return 1; 
    }; 

This way of defining a function is sometimes referred to as function literal notation.

The function () { return 1;} part is a function expression. A function expression can optionally have a name, in which case it becomes a named function expression (NFE). So, this is also allowed, although rarely seen in practice (and causes IE to mistakenly create two variables in the enclosing scope-f and myFunc):

    var f = function myFunc() { 
      return 1; 
    }; 

As you can see, there's no difference between a named function expression ...