Let's say I have an HTMLCollection:

const appElem = document.querySelector("#app");
const appChildren = appElem?.children; // HTML collection

now if I convert this collection to an array it will be Element[]:

const appChildrenArr = appChildren && Array.from(appChildren); // Element[]

But why appChildrenArr has Element[] type, not HTMLElement[] type?

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CodePudding user response：

Because they don't have to be HTMLElements. You could have an SVGElement there, as well, for example.

https://developer.mozilla.org/en-US/docs/Web/API/Element