This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The NodeList.length property returns the number of items in a NodeList.
An integer value representing the number of items in a NodeList.
The length property is often useful in DOM programming. It's often used to test the length of a list, to see if it exists at all. It's also commonly used as the iterator in a for loop, as in this example.
// All the paragraphs in the document
const items = document.getElementsByTagName("p");
// For each item in the list,
// append the entire element as a string of HTML
let gross = "";
for (let i = 0; i < items.length; i++) {
gross += items[i].innerHTML;
}
// gross is now all the HTML for the paragraphs
| Specification |
|---|
| DOM> # ref-for-dom-nodelist-length①> |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
length |
1 | 12 | 1 | ≤12.1 | 1 | 18 | 4 | ≤12.1 | 1 | 1.0 | 4.4 | 1 |
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https://developer.mozilla.org/en-US/docs/Web/API/NodeList/length