JQuery different methods for adding classes

I have seen a few different methods for adding classes to dynamically creat开发者_开发问答ed elements using JQuery.

I'm most familiar with

$("<div />").addClass("class1 class2");

however I have seen a lot of

$("<div />", {
  class : "class1 class2"
});

When I test out the second method in a Fiddle I can see both class1 and class2 are applied.

however, when applied to what i'm working on

// this does not work
var b = $("<div id='tweetBox' />", {
    class : "triangle-right right"
});

// this works
var b = $("<div id='tweetBox' />").addClass("triangle-right right");

you can't mix and match.

try:

var b = $("<div />", {
    id: "tweetBox",
    class : "triangle-right right"
});

// this does not work
var b = $("<div id='tweetBox' />", {
    class : "triangle-right right"
});

Doesn't work because there is an attribute on the element you are creating.

This will work
var b = $("<div />", {
    id: 'tweetBox',
    class : "triangle-right right"
});