getElementById and getSelection could return null

[Freddy03h]

Document getElementById

An Element object describing the DOM element object matching the specified ID, or null if no matching element was found in the document

DocumentFragment getElementById

An Element object describing the DOM element object matching the specified ID, or null if no matching element was found in the document fragment.

---

Window getSelection

A Selection object, or null if the associated document has no browsing context (for example, the window is an <iframe> that is not attached to a document).

When called on an <iframe> that is not displayed (e.g., where display: none is set) Firefox returns null, whereas other browsers returns a Selection object with Selection.type set to None.

Document getSelection

A Selection object, or null if the document has no browsing context (for example, it is the document of an <iframe> that is not attached to a document).

[nojaf]

Thanks!