Anonymous functions

We introduced you to anonymous functions a bit earlier in this chapter, and as they're a crucial concept, we will take a detailed look at them. For a language inspired by Scheme, anonymous functions are an important logical and structural construct.

Anonymous functions are typically used in cases where the function doesn't need to have a name for later reference. Let's look at some of the most popular usages of anonymous functions.

Anonymous functions while creating an object

An anonymous function can be assigned to an object property. When we do that, we can call that function with a dot (.) operator. If you are coming from a Java or other OO language background, you will find this very familiar. In such languages, a function, which is part of a class is generally called with a notation—Class.function(). Let's consider the following example:

var santa = {
  say :function(){ 
    console.log("ho ho ho"); 
  }
}
santa.say();

In this example, we are creating an object with a...