Chapter 4. Objects

Now that you've mastered JavaScript's primitive data types, arrays, and functions, it is time for the best part—objects. In this chapter, you will learn:

  • How to create and use objects

  • What are the constructor functions

  • What types of built-in JavaScript objects exist and what they can do for you

From Arrays to Objects

As you already know from Chapter 2, an array is just a list of values. Each value has an index (a numeric key) starting from zero and incrementing by one for each value.

>>>> var myarr = ['red', 'blue', 'yellow', 'purple'];
>>> myarr;

["red", "blue", "yellow", "purple"]

>>> myarr[0]

"red"

>>> myarr[3]

"purple"

If you put the indexes in one column and the values in another, you'll end up with a table of key/value ...

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