Is this an array?

[sepoto]

var myOptions = { zoom: 8, center: latlng, mapTypeId: google.maps.MapTypeId.ROADMAP }Is this an array? If I know exactly what it is I can read documentation about. Can someone please define?Thanks!

[justsomeguy]

That's an object literal.

[ShadowMage]

AKA, JavaScript Object Notation ( or JSON )

[thescientist]

That's an object literal.

which is a type of array, known as an associative array.

[justsomeguy]

Javascript doesn't have associative arrays, nor regular arrays technically. Everything in Javascript, including a numerical array, is an object.

[ShadowMage]

Javascript doesn't have associative arrays, nor regular arrays technically. Everything in Javascript, including a numerical array, is an object.

So can you access the elements of a numeric array using object syntax? Property names can't start with numbers so anArray.2 won't work...in fact it throws a "missing ) after argument list" error.var anArray = new Array(1, 2, 3, 4);alert(anArray.2);

[justsomeguy]

Right, variable and property names cannot start with numbers. There are internal mechanisms to match array syntax like arr[0] with the property.

[ShadowMage]

Right, variable and property names cannot start with numbers. There are internal mechanisms to match array syntax like arr[0] with the property.

In much the same way that obj["count"] is the same as obj.count?

[jeffman]

The big difference is that an object created with object notation does not have built-in array methods. For that you need an array object. (Or a bunch of work-arounds.)

[ShadowMage]

The big difference is that an object created with object notation does not have built-in array methods. For that you need an array object. (Or a bunch of work-arounds.)

Does that include array literals? Ie, arr = [1, 2, 3, 4];Or do those inherit the array methods.

[justsomeguy]

Yeah, creating an array literal creates a regular array object, with methods like push, pop, etc.

[boen_robot]

Does that include array literals? Ie, arr = [1, 2, 3, 4];Or do those inherit the array methods.

Yeah, creating an array literal creates a regular array object, with methods like push, pop, etc.

... or in other words, the "array literal" is what is commonly reffered to as "syntax sugar" - nothing new happening internally, but is added for convinience and briefness. Therefore:

var anArray = [1, 2, 3, 4];

and

var anArray = new Array(1, 2, 3, 4);

Internally do the same thing - create an array, which is initially filled with four elements with values 1, 2, 3 and 4, accessible from special properties called "index"-es, numbered as 0, 1, 2 and 3, respectively.And just to finish up with the "syntax sugar" thing, an "object literal" is also a syntax sugar, but the equivalent examples then become:

var myOptions = { zoom: 8, center: latlng, mapTypeId: google.maps.MapTypeId.ROADMAP }

and

var myOptions = new Object();myOptions.zoom = 8;myOptions.center = latlng;myOptions.mapTypeId = google.maps.MapTypeId.ROADMAP;

(the first is faster on most browsers, if not all, because it's done "at once", whereas the second fills the object property by property)

[ShadowMage]

Gotcha. Thx for the breakdown, boen_robot.