javascript

C H A P T E R 6
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Functions and Arrays
In the previous chapter, you learned about inheritance and saw how to pass members onto child objects
using classical, prototypal, deep copy, and mixin inheritance. As I noted at the end of that chapter, it’s
actually functions that are more often passed on to child objects. This is because common processes, as
provided by a function, are frequently more useful than common data, as provided by members. In this
chapter, I’ll cover why you would want to use functions and how to take advantage of function
inheritance. There are a lot of cool tricks to learn in this area and we’ll take advantage of a lot of them in
later chapters, as you’ll see from the copious forward references. In other words, this is quite an
important chapter.
In addition to the function subtype, arrays are a second subtype of the object value type. Arrays are
special primarily due to the predefined methods they inherit from Array.prototype. We’ll explore those
methods in this chapter.
Why Use Functions?
Ben & Jerry’s, Häagen-Dazs, and other French-style ice creams are made by creating a satiny custard
from cream, milk, and egg yolks. Compared to Philadelphia-style ice cream, which is made by simply
churning cream and milk, French-style ice cream can be tricky for a beginner to make. So, it’s best to
start with vanilla before gilding the lily. Err, gilding the orchid—vanilla flavoring derives from the fruit of
the vanilla orchid.
Anyway, the most delicious vanilla ice cream is made by steeping the pod and seeds from a vanilla
bean rather than by stirring in vanilla extract, which is less flavorful. Vanilla beans differ in taste
depending on where the vanilla orchids are grown. Madagascar Bourbon are my favorite. Compared to
those, Tahitian are milder in flavor, and Mexican are bolder.
If you are an ice-cream beginner, take your lumps with the following recipe for French vanilla before
gilding the orchid with chocolate, fruit, and so on:
1 cup, Organic Valley heavy whipping cream
2 cups, Organic Valley half & half
5/8 cup, sugar
6 egg yolks
1 Madagascar Bourbon vanilla bean
• Separate the egg yolks into mixing bowl.
• Slit the vanilla bean length-wise with a paring knife.
• Scrape the tiny, pasty seeds into a saucepan. Then add the empty pod halves—
most of the vanilla flavor derives from the pod.
• Add 2 cups half & half, 1/2 cup heavy whipping cream, and 5/8 cup sugar to
saucepan containing the vanilla seeds and pod halves.
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