Javascript: var map = {}; var list = [];

Question

Can someone tell me what exactly the two above lines of javascript do? And more importantly, what it's called so I can search some javascript references to learn about it? I assume they are both creating some form of an array that objects can be added to...?

Answer 1

It creates an empty dictionary in map and an empty array in list.

Read up on these structures at http://www.geocities.com/schools_ring/ArrayAndHash.html.

Answer 2

Curly braces are syntax for creating a Javascript object (which is really a glorified collection of key/value pairs); the brackets make a resizable array.

These are called literals, and they're a handy shortcut to help you make objects and arrays without a lot of typing (good, because you use them all the time). Many other programming languages have similar literal syntax for maps and arrays.