How do I enumerate all of the html id's in a document with javascript?

Question

I would like to be able to use javascript to find every id (or name) for every object in an html document so that they can be printed at the bottom of the page.

To under

Answer 1

with jQuery

$('*').map(function() {
   return this.id || null;
}).get().join(',');

this gets all the elements in the DOM, and runs a function on each to return the id (and if undefined, returning null won't return anything. This returns a jQuery object which is then converted to a JavaScript array with get() and this is then converted to a comma-separated string of ids.

Try it on this page and you get

"notify-container,overlay-header,custom-header,header,portalLink,topbar,hlinks,hlinks-user,hlinks-nav,hlinks-custom,hsearch,search,hlogo,hmenus,nav-questions,nav-tags,nav-users,nav-badges,nav-unanswered,nav-askquestion,content,question-header,mainbar,question,edit-tags,link-post-7115022,close-question-7115022,flag-post-7115022,comments-7115022,add-comment-7115022,comments-link-7115022,answers,answers-header,tabs,answer-7115033,link-post-7115033,flag-post-7115033,comments-7115033,add-comment-7115033,comments-link-7115033,answer-7115042,link-post-7115042,flag-post-7115042,comments-7115042,add-comment-7115042,comments-link-7115042,answer-7115043,link-post-7115043,delete-post-7115043,flag-post-7115043,post-editor-7115043,wmd-button-bar-7115043,wmd-button-row-7115043,wmd-bold-button-7115043,wmd-italic-button-7115043,wmd-spacer1-7115043,wmd-link-button-7115043,wmd-quote-button-7115043,wmd-code-button-7115043,wmd-image-button-7115043,wmd-spacer2-7115043,wmd-olist-button-7115043,wmd-ulist-button-7115043,wmd-heading-button-7115043,wmd-hr-button-7115043,wmd-spacer3-7115043,wmd-undo-button-7115043,wmd-redo-button-7115043,wmd-help-button-7115043,wmd-input-7115043,draft-saved-7115043,communitymode-7115043,wmd-preview-7115043,fkey,author,edit-comment-7115043,edit-comment-error-7115043,submit-button-7115043,comments-7115043,add-comment-7115043,comments-link-7115043,post-form,post-editor,wmd-button-bar,wmd-input,draft-saved,communitymode,wmd-preview,fkey,author,submit-button,show-editor-button,sidebar,qinfo,adzerk2,newsletter-ad,newsletter-ad-header,newsletter-signup-container,newsletter-signup,newsletter-preview-container,newsletter-preview,h-related,feed-link,feed-link-text,prettify-lang,footer,footer-menu,footer-sites,footer-flair,svnrev,copyright"