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Change all ID values by same Class name

I am using the "Autofill" extention on Google Chrome which runs javascript codes. I want to change all ID's ctl01_ctl00_Main_Main_wtWeighted_txtWeight_xxxxx numeric values from 0 to 100 by same Class name weightBox Numeric.
My best guess was the code below but nothing.
document.getElementsByClassName('weightBox Numeric').value = "100";

getElementsByClassName() returns a live collection. In other words, it's a sort of array. So you have to loop through each value to change them. Also you can use querySelectorAll here:
var elements = document.querySelectorAll(".weightBox.Numeric");
for (var i = 0; i < elements.length; i++) {
elements[i].id = i + 1;
}

Delete object by attribute in javascript

I have a few different tables on the same page but unfortunately they were not assigned any unique id's. I want to remove a table using a JS command, but since id cannot be used, is it possible to delete a table based on a certain attribute it has? For example, is there a command to delete all tables on the page that have the attribute: width="25%" ?

You can use querySelectorAll to do that.
var x = document.querySelectorAll("table[width='25%']");
for (var i=0; i<x.length; i++) { //returns array of elements that match the attribute selector
x[i].remove(); //call prototype method defined below
}
Removing is tricky, I found this code that makes a nice remove method
Element.prototype.remove = function() {
this.parentElement.removeChild(this);
}
NodeList.prototype.remove = HTMLCollection.prototype.remove = function() {
for(var i = 0, len = this.length; i < len; i++) {
if(this[i] && this[i].parentElement) {
this[i].parentElement.removeChild(this[i]);
}
}
}
This creates a prototype remove() function that iterates the node and deletes the children.
Please note that querySelectorAll will not work in IE8 or below, but the poster of the prototype method said that it should work in IE8 but not 7.

I know this already has some solutions, but I'll offer up one more alternative.
var tables = document.getElementsByTagName('table');
for(var i = 0; i < tables.length; i++){
if(tables[i].getAttribute('width') == "25%"){
tables[i].parentNode.removeChild(tables[i]);
}
}
Demo at http://codepen.io/michaelehead/pen/HfdKx.

Yes you can. The easiest way is to use JQuery.
In your javascript code you would just write:
$("[attribute=value]").remove()
So in your case it could be something like $("table[width='25%']").remove()

For cycle or for each with js objects

I got a problem to add a onclick event to object who can be many times in same page
I am trying to
var i;
for (i = 1; i<=10; i++) {
var tmpObj='lov_DgId_D_'+i;
var tmpObj2=tmpObj.getElementsByTagName('a')[0];
if (tmpObj2 != null) {
tmpObj2.onclick= DgIdOnClick;
}
}
But got a error TypeError:
Object lov_DgId_D_1 has no method 'getElementsByTagName' , but this is working
lov_DgId_D_2.getElementsByTagName('a')[0].onclick= DgIdOnClick;
This ibject lov_DgId_D_ can be from 1 like lov_DgId_D_1 or lov_DgId_D_99 u.t.c
What wil be the best solution to add onclick to all lov_DgId_D_* objects ?

As you use jquery, the simplest is
for (i = 1; i<=10; i++) {
$('#lov_DgId_D_'+ i+ ' a').click(DgIdOnClick);
}
If you want to bind your event handler to all a elements inside elements whose id starts with lov_DgId_D_, then it's as simple as
$('[id^="lov_DgId_D_"] a').click(DgIdOnClick);

The problem you have is a confusion between the id of an element and the actual element. Some code that should work for you is this one:
var i;
for (i = 1; i<=10; i++) {
var tmpObj=document.getElementById('lov_DgId_D_'+i); // <-- here
var tmpObj2=tmpObj.getElementsByTagName('a')[0];
if (tmpObj2 != null) {
tmpObj2.onclick= DgIdOnClick;
}
}
Slightly easier to read code:
for (var i=0; i<=10; i++) {
var anchor = document.querySelector('#lov_DgId_D_'+i + ' a');
if (anchor) anchor.onclick = DgIdOnClick;
}
A note: this code attaches a click event to the first anchor (a element) inside each element with the id lov_DgId_D_n, with n being 1->10. Your original code seems to want to do the same thing.
Another note: usually when you iterate over elements using their id's to identify them, you are better suited to add a class to those elements instead. It provides for more maintaintable code and probably easier to understand as well.

ID Ends With in pure Javascript

I am working in a Javascript library that brings in jQuery for one thing: an "ends with" selector. It looks like this:
$('[id$=foo]')
It will find the elements in which the id ends with "foo".
I am looking to do this without jQuery (straight JavaScript). How might you go about this? I'd also like it to be as efficient as reasonably possible.

Use querySelectorAll, not available in all browsers (like IE 5/6/7/8) though. It basically works like jQuery:
http://jsfiddle.net/BBaFa/2/
console.log(document.querySelectorAll("[id$=foo]"));

You will need to iterate over all elements on the page and then use string functions to test it. The only optimizations I can think of is changing the starting point - i.e. not document.body but some other element where you know your element will be a child of - or you could use document.getElementsByTagName() to get an element list if you know the tag name of the elements.
However, your task would be much easier if you could use some 3rd-party-javascript, e.g. Sizzle (4k minified, the same selector engine jQuery uses).

So, using everything that was said, I put together this code. Assuming my elements are all inputs, then the following code is probably the best I am going to get?
String.prototype.endsWith = function(suffix) {
return this.indexOf(suffix, this.length - suffix.length) !== -1;
};
function getInputsThatEndWith(text) {
var result = new Array();
var inputs = document.getElementsByTagName("input");
for(var i=0; i < inputs.length; i++) {
if(inputs[i].id.endsWith(text))
result.push(inputs[i]);
}
return result;
}
I put it on JsFiddle: http://jsfiddle.net/MF29n/1/

#ThiefMaster touched on how you can do the check, but here's the actual code:
function idEndsWith(str)
{
if (document.querySelectorAll)
{
return document.querySelectorAll('[id$="'+str+'"]');
}
else
{
var all,
elements = [],
i,
len,
regex;
all = document.getElementsByTagName('*');
len = all.length;
regex = new RegExp(str+'$');
for (i = 0; i < len; i++)
{
if (regex.test(all[i].id))
{
elements.push(all[i]);
}
}
return elements;
}
}
This can be enhanced in a number of ways. It currently iterates through the entire dom, but would be more efficient if it had a context:
function idEndsWith(str, context)
{
if (!context)
{
context = document;
}
...CODE... //replace all occurrences of "document" with "context"
}
There is no validation/escaping on the str variable in this function, the assumption is that it'll only receive a string of chars.

Suggested changes to your answer:
RegExp.quote = function(str) {
return str.replace(/([.?*+^$[\]\\(){}-])/g, "\\$1");
}; // from https://stackoverflow.com/questions/494035/#494122
String.prototype.endsWith = function(suffix) {
return !!this.match(new RegExp(RegExp.quote(suffix) + '$'));
};
function getInputsThatEndWith(text) {
var results = [],
inputs = document.getElementsByTagName("input"),
numInputs = inputs.length,
input;
for(var i=0; i < numInputs; i++) {
var input = inputs[i];
if(input.id.endsWith(text)) results.push(input);
}
return results;
}
http://jsfiddle.net/mattball/yJjDV/
Implementing String.endsWith using a regex instead of indexOf() is mostly a matter of preference, but I figured it was worth including for variety. If you aren't concerned about escaping special characters in the suffix, you can remove the RegExp.quote() bit, and just use
new RegExp(suffix + '$').

If you know the type of DOM elements you are targeting,
then get a list of references to them using getElementsByTagName , and then iterate over them.
You can use this optimization to fasten the iterations:
ignore the elements not having id.
target the nearest known parent of elements you want to seek, lets say your element is inside a div with id='myContainer', then you can get a restricted subset using
document.getElementById('myContainer').getElementsByTagName('*') , and then iterate over them.

How can I loop through ALL DOM elements on a page?

I'm trying to loop over ALL elements on a page, so I want to check every element that exists on this page for a special class.
So, how do I say that I want to check EVERY element?

You can pass a * to getElementsByTagName() so that it will return all elements in a page:
var all = document.getElementsByTagName("*");
for (var i=0, max=all.length; i < max; i++) {
// Do something with the element here
}
Note that you could use querySelectorAll(), if it's available (IE9+, CSS in IE8), to just find elements with a particular class.
if (document.querySelectorAll)
var clsElements = document.querySelectorAll(".mySpeshalClass");
else
// loop through all elements instead
This would certainly speed up matters for modern browsers.
Browsers now support foreach on NodeList. This means you can directly loop the elements instead of writing your own for loop.
document.querySelectorAll('*').forEach(function(node) {
// Do whatever you want with the node object.
});
Performance note - Do your best to scope what you're looking for by using a specific selector. A universal selector can return lots of nodes depending on the complexity of the page. Also, consider using document.body.querySelectorAll instead of document.querySelectorAll when you don’t care about <head> children.

Was looking for same. Well, not exactly. I only wanted to list all DOM Nodes.
var currentNode,
ni = document.createNodeIterator(document.documentElement, NodeFilter.SHOW_ELEMENT);
while(currentNode = ni.nextNode()) {
console.log(currentNode.nodeName);
}
To get elements with a specific class, we can use filter function.
var currentNode,
ni = document.createNodeIterator(
document.documentElement,
NodeFilter.SHOW_ELEMENT,
function(node){
return node.classList.contains('toggleable') ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_REJECT;
}
);
while(currentNode = ni.nextNode()) {
console.log(currentNode.nodeName);
}
Found solution on
MDN

As always the best solution is to use recursion:
loop(document);
function loop(node){
// do some thing with the node here
var nodes = node.childNodes;
for (var i = 0; i <nodes.length; i++){
if(!nodes[i]){
continue;
}
if(nodes[i].childNodes.length > 0){
loop(nodes[i]);
}
}
}
Unlike other suggestions, this solution does not require you to create an array for all the nodes, so its more light on the memory. More importantly, it finds more results. I am not sure what those results are, but when testing on chrome it finds about 50% more nodes compared to document.getElementsByTagName("*");

Here is another example on how you can loop through a document or an element:
function getNodeList(elem){
var l=new Array(elem),c=1,ret=new Array();
//This first loop will loop until the count var is stable//
for(var r=0;r<c;r++){
//This loop will loop thru the child element list//
for(var z=0;z<l[r].childNodes.length;z++){
//Push the element to the return array.
ret.push(l[r].childNodes[z]);
if(l[r].childNodes[z].childNodes[0]){
l.push(l[r].childNodes[z]);c++;
}//IF
}//FOR
}//FOR
return ret;
}

For those who are using Jquery
$("*").each(function(i,e){console.log(i+' '+e)});

Andy E. gave a good answer.
I would add, if you feel to select all the childs in some special selector (this need happened to me recently), you can apply the method "getElementsByTagName()" on any DOM object you want.
For an example, I needed to just parse "visual" part of the web page, so I just made this
var visualDomElts = document.body.getElementsByTagName('*');
This will never take in consideration the head part.

from this link
javascript reference
<html>
<head>
<title>A Simple Page</title>
<script language="JavaScript">
<!--
function findhead1()
{
var tag, tags;
// or you can use var allElem=document.all; and loop on it
tags = "The tags in the page are:"
for(i = 0; i < document.all.length; i++)
{
tag = document.all(i).tagName;
tags = tags + "\r" + tag;
}
document.write(tags);
}
// -->
</script>
</head>
<body onload="findhead1()">
<h1>Heading One</h1>
</body>
</html>
UPDATE:EDIT
since my last answer i found better simpler solution
function search(tableEvent)
{
clearResults()
document.getElementById('loading').style.display = 'block';
var params = 'formAction=SearchStocks';
var elemArray = document.mainForm.elements;
for (var i = 0; i < elemArray.length;i++)
{
var element = elemArray[i];
var elementName= element.name;
if(elementName=='formAction')
continue;
params += '&' + elementName+'='+ encodeURIComponent(element.value);
}
params += '&tableEvent=' + tableEvent;
createXmlHttpObject();
sendRequestPost(http_request,'Controller',false,params);
prepareUpdateTableContents();//function js to handle the response out of scope for this question
}

Getting all elements using var all = document.getElementsByTagName("*"); for (var i=0, max=all.length; i < max; i++); is ok if you need to check every element but will result in checking or looping repeating elements or text.
Below is a recursion implementation that checks or loop each element of all DOM elements only once and append:
(Credits to #George Reith for his recursion answer here: Map HTML to JSON)
function mapDOMCheck(html_string, json) {
treeObject = {}
dom = new jsdom.JSDOM(html_string) // use jsdom because DOMParser does not provide client-side Window for element access
document = dom.window.document
element = document.querySelector('html')
// Recurse and loop through DOM elements only once
function treeHTML(element, object) {
var nodeList = element.childNodes;
if (nodeList != null) {
if (nodeList.length) {
object[element.nodeName] = []; // IMPT: empty [] array for parent node to push non-text recursivable elements (see below)
for (var i = 0; i < nodeList.length; i++) {
console.log("nodeName", nodeList[i].nodeName);
if (nodeList[i].nodeType == 3) { // if child node is **final base-case** text node
console.log("nodeValue", nodeList[i].nodeValue);
} else { // else
object[element.nodeName].push({}); // push {} into empty [] array where {} for recursivable elements
treeHTML(nodeList[i], object[element.nodeName][object[element.nodeName].length - 1]);
}
}
}
}
}
treeHTML(element, treeObject);
}

Use *
var allElem = document.getElementsByTagName("*");
for (var i = 0; i < allElem.length; i++) {
// Do something with all element here
}

i think this is really quick
document.querySelectorAll('body,body *').forEach(function(e) {

You can try with
document.getElementsByClassName('special_class');