length returns the number of items in a NodeList.
numItems = nodeList.length
numItems is an integer value representing the number of items in a NodeList.// all the paragraphs in the document
var items = document.getElementsByTagName("p");
// for each item in the list,
// append the entire element as a string of HTML
var gross = "";
for (var i = 0; i < items.length; i++) {
gross += items[i].innerHTML;
}
// gross is now all the HTML for the paragraphs
Despite the location of this page in the reference, length is not a property of Element, but rather of a NodeList. NodeList objects are returned from a number of DOM methods, such as document.getElementsByTagName.
length is a very common property in DOM programming. It's normal to test the length of a list (to see if it exists at all) and to use it as the iterator in a for loop, as in the example above.
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | 1 | 12 | ? | ? | ? | ? |
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | ? | ? | ? | ? | Yes |
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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/NodeList/length