What do curly braces in JavaScript mean?

I found this in a jQuery file:

xxx.css({ 'float' : 'right' });

What do the curly braces do?

In your case it is an object passed to your css function.

myObj={} // a blank object

Here you can use this too

myObj={'float' : 'right'}
xxx.css(myObj);

Here is another example of object

var myObj={
    'varOne':'One',
    'methodOne':function(){ alert('methodOne has been called!')}        
}
myObj.methodOne();​ // It will alert 'methodOne has been called!'

A fiddle is here.

The curly braces in the code you've shown define an object literal

In javascript curly braces are used for several purposes.

I your case these are used to create a key-value pair.

In others cases curly braces are used to combine a set of statements in a block. And sometimes they are used to create objects like var abc = { "a": 1, "b": 2 };

This is the top search engine result for "javascript braces". As such it's worth mentioning that braces in JavaScript can be used for:

• An object literal

• A code block

• Object destructuring

It's an object literal.

var x = {'float': 'right'} is the nicer/shorter form of var x = new Object(); x.float = 'right';

Basically the curly braces {} are the another way for creating objects in javascript. This is equivalent to the "new Object()" syntax.

curly braces identify an Object like so:

timObject = {
	property1 : "Hello",
	property2 : "MmmMMm",
	property3 : ["mmm", 2, 3, 6, "kkk"],
	method1 : function(){alert("Method had been called" + this.property1)}
};

in jQuery they are used to provide an Object with options for your method. You could also write your code like so xxx.css("width","10px").css("font-size","30px"); But passing it an Object makes it faster and more readable

xxx.css({"width":"10px","font-size":"20px"});

• http://docs.jquery.com/Types#Object

Creates an object.

var myObject = {"element" : "value"};
alert(myObject.element); // Would alert: "value"

That is an object literal

> An object literal is a list of zero or more pairs of property names and associated values of an object

They encapsualte the css attributes in this example.

Normally curly brackets represent a function or an encapsulated piece of code that needs to be executed as one.