?我可以这样做:还是我应该使用 removeElement 的某种组合?我希望答案是直接的 DOM;如果您还在 jQuery 中提供答案以及仅 DOM 的答案,则可以加分。" />
?我可以这样做:还是我应该使用 removeElement 的某种组合?我希望答案是直接的 DOM;如果您还在 jQuery 中提供答案以及仅 DOM 的答案,则可以加分。"> ?我可以这样做:还是我应该使用 removeElement 的某种组合?我希望答案是直接的 DOM;如果您还在 jQuery 中提供答案以及仅 DOM 的答案,则可以加分。" />How would I go about removing all of the child elements of a DOM node in JavaScript?
Say I have the following (ugly) HTML:
<p id="foo">
<span>hello</span>
<div>world</div>
</p>
And I grab the node I want like so:
var myNode = document.getElementById("foo");
How could I remove the children of foo
so that just <p id="foo"></p>
is left?
Could I just do:
myNode.childNodes = new Array();
or should I be using some combination of removeElement
?
I'd like the answer to be straight up DOM; though extra points if you also provide an answer in jQuery along with the DOM-only answer.
Option 1 A: Clearing innerHTML.
This approach is simple, but might not be suitable for high-performance applications because it invokes the browser's HTML parser (though browsers may optimize for the case where the value is an empty string).
doFoo.onclick = () => { const myNode = document.getElementById("foo"); myNode.innerHTML = ''; }
Option 1 B: Clearing textContent
As above, but use .textContent. According to MDN this will be faster than innerHTML as browsers won't invoke their HTML parsers and will instead immediately replace all children of the element with a single #text node.
doFoo.onclick = () => { const myNode = document.getElementById("foo"); myNode.textContent = ''; }
Option 2 A: Looping to remove every lastChild:
An earlier edit to this answer used firstChild, but this is updated to use lastChild as in computer-science, in general, it's significantly faster to remove the last element of a collection than it is to remove the first element (depending on how the collection is implemented).
The loop continues to check for firstChild just in case it's faster to check for firstChild than lastChild (e.g. if the element list is implemented as a directed linked-list by the UA).
doFoo.onclick = () => { const myNode = document.getElementById("foo"); while (myNode.firstChild) { myNode.removeChild(myNode.lastChild); } }
Option 2 B: Looping to remove every lastElementChild:
This approach preserves all non-Element (namely #text nodes and ) children of the parent (but not their descendants) - and this may be desirable in your application (e.g. some templating systems that use inline HTML comments to store template instructions).
This approach wasn't used until recent years as Internet Explorer only added support for lastElementChild in IE9.
doFoo.onclick = () => { const myNode = document.getElementById("foo"); while (myNode.lastElementChild) { myNode.removeChild(myNode.lastElementChild); } }
Bonus: Element.clearChildren monkey-patch:
We can add a new method-property to the Element prototype in JavaScript to simplify invoking it to just el.clearChildren() (where el is any HTML element object).
(Strictly speaking this is a monkey-patch, not a polyfill, as this is not a standard DOM feature or missing feature. Note that monkey-patching is rightfully discouraged in many situations.)
if( typeof Element.prototype.clearChildren === 'undefined' ) { Object.defineProperty(Element.prototype, 'clearChildren', { configurable: true, enumerable: false, value: function() { while(this.firstChild) this.removeChild(this.lastChild); } }); }
In 2022+, use the replaceChildren() API!
Replacing all children can now be done with the (cross-browser supported) replaceChildren
API:
container.replaceChildren(...arrayOfNewChildren);
This will do both:
remove all existing children, and
append all of the given new children, in one operation.
You can also use this same API to just remove existing children, without replacing them:
container.replaceChildren();
This is fully supported in Chrome/Edge 86+, Firefox 78+, and Safari 14+. It is fully specified behavior. This is likely to be faster than any other proposed method here, since the removal of old children and addition of new children is done without requiring innerHTML
, and in one step instead of multiple.
textContent
is much faster for hundreds of children. (I mean you can do this, but always set textContent
to remove many existing children first.)
Use modern Javascript, with remove!
const parent = document.getElementById("foo")
while (parent.firstChild) {
parent.firstChild.remove()
}
This is a newer way to write node removal in ES5. It is vanilla JS and reads much nicer than relying on parent.
All modern browsers are supported.
Browser Support - 97% Jun '21
while (parent.firstChild) { parent.removeChild(parent.firstChild); }
loop. developer.mozilla.org/en-US/docs/Web/API/ParentNode/children developer.mozilla.org/en-US/docs/Web/API/Node/childNodes
while (parent.firstChild && !parent.firstChild.remove());
[...parent.childNodes].forEach(el => el.remove());
while (selectElem.firstElementChild) { selectElem.firstElementChild.remove(); }
The currently accepted answer is wrong about innerHTML
being slower (at least in IE and Chrome), as m93a correctly mentioned.
Chrome and FF are dramatically faster using this method (which will destroy attached jquery data):
var cNode = node.cloneNode(false);
node.parentNode.replaceChild(cNode, node);
in a distant second for FF and Chrome, and fastest in IE:
node.innerHTML = '';
InnerHTML won't destroy your event handlers or break jquery references, it's also recommended as a solution here: https://developer.mozilla.org/en-US/docs/Web/API/Element.innerHTML.
The fastest DOM manipulation method (still slower than the previous two) is the Range removal, but ranges aren't supported until IE9.
var range = document.createRange();
range.selectNodeContents(node);
range.deleteContents();
The other methods mentioned seem to be comparable, but a lot slower than innerHTML, except for the outlier, jquery (1.1.1 and 3.1.1), which is considerably slower than anything else:
$(node).empty();
Evidence here:
http://jsperf.com/innerhtml-vs-removechild/167
http://jsperf.com/innerhtml-vs-removechild/300
https://jsperf.com/remove-all-child-elements-of-a-dom-node-in-javascript (New url for jsperf reboot because editing the old url isn't working)
Jsperf's "per-test-loop" often gets understood as "per-iteration", and only the first iteration has nodes to remove so the results are meaningless, at time of posting there were tests in this thread set up incorrectly.
jQuery.cache
, causing a memory leak because the only reference available to manage that data was on the elements you just destroyed.
innerHTML
is still the winner. I've spent too long on this rabbit hole already, but in the year 2020 I have to wonder why we don't have a .clear()
or .empty()
DOM method yet...
If you use jQuery:
$('#foo').empty();
If you don't:
var foo = document.getElementById('foo');
while (foo.firstChild) foo.removeChild(foo.firstChild);
var myNode = document.getElementById("foo");
var fc = myNode.firstChild;
while( fc ) {
myNode.removeChild( fc );
fc = myNode.firstChild;
}
If there's any chance that you have jQuery affected descendants, then you must use some method that will clean up jQuery data.
$('#foo').empty();
The jQuery .empty()
method will ensure that any data that jQuery associated with elements being removed will be cleaned up.
If you simply use DOM
methods of removing the children, that data will remain.
while ( myNode.firstChild ) {
while(fc = myNode.firstChild){ myNode.removeChild(fc); }
The fastest...
var removeChilds = function (node) {
var last;
while (last = node.lastChild) node.removeChild(last);
};
Thanks to Andrey Lushnikov for his link to jsperf.com (cool site!).
EDIT: to be clear, there is no performance difference in Chrome between firstChild and lastChild. The top answer shows a good solution for performance.
Use elm.replaceChildren()
.
It’s experimental without wide support, but when executed with no params will do what you’re asking for, and it’s more efficient than looping through each child and removing it. As mentioned already, replacing innerHTML
with an empty string will require HTML parsing on the browser’s part.
Update It's widely supported now
If you only want to have the node without its children you could also make a copy of it like this:
var dupNode = document.getElementById("foo").cloneNode(false);
Depends on what you're trying to achieve.
parent.replaceChild(cloned, original)
? That might be faster than removing children one by one and should work on everything that supports the DOM (so every type of XML document, including SVG). Setting innerHTML might also be faster than removing children one by one, but that doesn't work on anything but HTML documents. Should test that some time.
addEventListener
.
Ecma6 makes it easy and compact
myNode.querySelectorAll('*').forEach( n => n.remove() );
This answers the question, and removes “all child nodes”.
If there are text nodes belonging to myNode
they can’t be selected with CSS selectors, in this case we’ve to apply (also):
myNode.textContent = '';
Actually the last one could be the fastest and more effective/efficient solution.
.textContent
is more efficient than .innerText
and .innerHTML
, see: MDN
Here's another approach:
function removeAllChildren(theParent){
// Create the Range object
var rangeObj = new Range();
// Select all of theParent's children
rangeObj.selectNodeContents(theParent);
// Delete everything that is selected
rangeObj.deleteContents();
}
element.textContent = '';
It's like innerText, except standard. It's a bit slower than removeChild()
, but it's easier to use and won't make much of a performance difference if you don't have too much stuff to delete.
Here is what I usually do :
HTMLElement.prototype.empty = function() {
while (this.firstChild) {
this.removeChild(this.firstChild);
}
}
And voila, later on you can empty any dom element with :
anyDom.empty()
domEl.innerHTML = ""
is poor and considered bad practice
In response to DanMan, Maarten and Matt. Cloning a node, to set the text is indeed a viable way in my results.
// @param {node} node
// @return {node} empty node
function removeAllChildrenFromNode (node) {
var shell;
// do not copy the contents
shell = node.cloneNode(false);
if (node.parentNode) {
node.parentNode.replaceChild(shell, node);
}
return shell;
}
// use as such
var myNode = document.getElementById('foo');
myNode = removeAllChildrenFromNode( myNode );
Also this works for nodes not in the dom which return null when trying to access the parentNode. In addition, if you need to be safe a node is empty before adding content this is really helpful. Consider the use case underneath.
// @param {node} node
// @param {string|html} content
// @return {node} node with content only
function refreshContent (node, content) {
var shell;
// do not copy the contents
shell = node.cloneNode(false);
// use innerHTML or you preffered method
// depending on what you need
shell.innerHTML( content );
if (node.parentNode) {
node.parentNode.replaceChild(shell, node);
}
return shell;
}
// use as such
var myNode = document.getElementById('foo');
myNode = refreshContent( myNode );
I find this method very useful when replacing a string inside an element, if you are not sure what the node will contain, instead of worrying how to clean up the mess, start out fresh.
Using a range loop feels the most natural to me:
for (var child of node.childNodes) {
child.remove();
}
According to my measurements in Chrome and Firefox, it is about 1.3x slower. In normal circumstances, this will perhaps not matter.
There are couple of options to achieve that:
The fastest ():
while (node.lastChild) {
node.removeChild(node.lastChild);
}
Alternatives (slower):
while (node.firstChild) {
node.removeChild(node.firstChild);
}
while (node.hasChildNodes()) {
node.removeChild(node.lastChild);
}
Benchmark with the suggested options
var empty_element = function (element) {
var node = element;
while (element.hasChildNodes()) { // selected elem has children
if (node.hasChildNodes()) { // current node has children
node = node.lastChild; // set current node to child
}
else { // last child found
console.log(node.nodeName);
node = node.parentNode; // set node to parent
node.removeChild(node.lastChild); // remove last node
}
}
}
This will remove all nodes within the element.
innerText is the winner! http://jsperf.com/innerhtml-vs-removechild/133. At all previous tests inner dom of parent node were deleted at first iteration and then innerHTML or removeChild where applied to empty div.
innerText
is a proprietary MS thing though. Just saying.
box
being available not as a var but through DOM lookup based on id, and since the while
loop makes this slow call many times it's penalized.
Simplest way of removing the child nodes of a node via Javascript
var myNode = document.getElementById("foo");
while(myNode.hasChildNodes())
{
myNode.removeChild(myNode.lastChild);
}
let el = document.querySelector('#el');
if (el.hasChildNodes()) {
el.childNodes.forEach(child => el.removeChild(child));
}
i saw people doing:
while (el.firstNode) {
el.removeChild(el.firstNode);
}
then someone said using el.lastNode
is faster
however I would think that this is the fastest:
var children = el.childNodes;
for (var i=children.length - 1; i>-1; i--) {
el.removeNode(children[i]);
}
what do you think?
ps: this topic was a life saver for me. my firefox addon got rejected cuz i used innerHTML. Its been a habit for a long time. then i foudn this. and i actually noticed a speed difference. on load the innerhtml took awhile to update, however going by addElement its instant!
for (var i=0...
one though. But here is what i got when i ran those tests: i.imgur.com/Mn61AmI.png so in those three tests firstNode was faster than lastNode and innerHTML which is real cool
Why aren't we following the simplest method here "remove" looped inside while.
const foo = document.querySelector(".foo");
while (foo.firstChild) {
foo.firstChild.remove();
}
Selecting the parent div
Using "remove" Method inside a While loop for eliminating First child element , until there is none left.
Generally, JavaScript uses arrays to reference lists of DOM nodes. So, this will work nicely if you have an interest in doing it through the HTMLElements array. Also, worth noting, because I am using an array reference instead of JavaScript proto's this should work in any browser, including IE.
while(nodeArray.length !== 0) {
nodeArray[0].parentNode.removeChild(nodeArray[0]);
}
Just saw someone mention this question in another and thought I would add a method I didn't see yet:
function clear(el) {
el.parentNode.replaceChild(el.cloneNode(false), el);
}
var myNode = document.getElementById("foo");
clear(myNode);
The clear function is taking the element and using the parent node to replace itself with a copy without it's children. Not much performance gain if the element is sparse but when the element has a bunch of nodes the performance gains are realized.
Functional only approach:
const domChildren = (el) => Array.from(el.childNodes)
const domRemove = (el) => el.parentNode.removeChild(el)
const domEmpty = (el) => domChildren(el).map(domRemove)
"childNodes" in domChildren will give a nodeList of the immediate children elements, which is empty when none are found. In order to map over the nodeList, domChildren converts it to array. domEmpty maps a function domRemove over all elements which removes it.
Example usage:
domEmpty(document.body)
removes all children from the body element.
element.innerHTML = ""
(or .textContent) is by far the fastest solution
Most of the answers here are based on flawed tests
For example: https://jsperf.com/innerhtml-vs-removechild/15
This test does not add new children to the element between each iteration. The first iteration will remove the element's contents, and every other iteration will then do nothing. In this case, while (box.lastChild) box.removeChild(box.lastChild)
was faster because box.lastChild was null
99% of the time
Here is a proper test: https://jsperf.com/innerhtml-conspiracy
Finally, do not use node.parentNode.replaceChild(node.cloneNode(false), node)
. This will replace the node with a copy of itself without its children. However, this does not preserve event listeners and breaks any other references to the node.
Best Removal Method for ES6+ Browser (major browsers released after year 2016):
Perhaps there are lots of way to do it, such as Element.replaceChildren(). I would like to show you an effective solution with only one redraw & reflow supporting all ES6+ browsers.
function removeChildren(cssSelector, parentNode){
var elements = parentNode.querySelectorAll(cssSelector);
let fragment = document.createDocumentFragment();
fragment.textContent=' ';
fragment.firstChild.replaceWith(...elements);
}
Usage: removeChildren('.foo',document.body);
: remove all elements with className foo
in <body>
textContent
just do fragment.replaceChildren(...elements)
instead of fragment.firstChild.replaceWith(...elements)
replaceChildren
is a relatively new DOM method. (e.g. FireFox >=78) while replaceWith
can run with Firefox>=49. If your target browsers are the latest versions without considering Waterfox Classic, replaceChildren
could be better.
You can remove all child elements from a container like below:
function emptyDom(selector){
const elem = document.querySelector(selector);
if(elem) elem.innerHTML = "";
}
Now you can call the function and pass the selector like below:
If element has id = foo
emptyDom('#foo');
If element has class = foo
emptyDom('.foo');
if element has tag =
emptyDom('div')
I did it like this
data = {
"messages": [
[0, "userName", "message test"],
[1, "userName1", "message test1"]
]
}
for (let i = 0; i < data.messages.length; i++) {
var messageData = document.createElement('span')
messageData.className = 'messageClass'
messageData.innerHTML = `${data.messages[i][2]} ${'
'}`
$(".messages").append(messageData)
}
$('#removeMessages').on('click', () => {
node = $('.messages').get(0)
while (node.firstChild) {
node.firstChild.remove()
}
$('#removeMessages').toggle(500)
$('#addMessages').toggle(500)
})
$('#addMessages').on('click', () => {
for (let i = 0; i < data.messages.length; i++) {
var messageData = document.createElement('span')
messageData.className = 'messageClass'
messageData.innerHTML = `${data.messages[i][2]} ${'
'}`
$(".messages").append(messageData)
}
$('#addMessages').toggle(500)
$('#removeMessages').toggle(500)
}) #addMessages{
display:none;
}
simply only IE:
parentElement.removeNode(true);
true
- means to do deep removal - which means that all child are also removed
Success story sharing
innerHTML = ''
is slower, but I don't think it's "wrong". Any claims of memory leaks should be backed up with evidence.